NL2034275B1

NL2034275B1 - Optical lens

Info

Publication number: NL2034275B1
Application number: NL2034275A
Authority: NL
Inventors: Wilfried Cecile Marchal Paul; Bisschop Suzanne; De Smet Jelle
Original assignee: Morrow Nv
Priority date: 2023-03-06
Filing date: 2023-03-06
Publication date: 2024-09-18

Abstract

An optical lens, for example a spectacle lens, intended to be carried in front of an eye of a user, is provided. The optical lens comprises a ﬁrst refraction area having a ﬁrst refractive power conﬁgured to focus an image on the retina of the eye of the user, a second refraction area having a second refractive power different from the ﬁrst refractive power, and being conﬁgured to focusing the image on a position in front of or behind the retina of the eye of the user, wherein the refractive power of at least a portion of the second refraction area of the optical lens is tunable.

Description

OPTICAL LENS

The disclosure relates to an optical lens, for example a spectacle lens, intended to be carried in front of an eye of a user. The optical lens comprises a first refraction area having a first refractive power configured to focus an image on the retina of the eye of the user, and a second refraction area having a second refractive power different from the first refractive power and being configured to focusing the image on a position in front of or behind the retina of the eye of the user. The disclosure also relates to an assembly comprising one or more of such optical lenses and a controller connected to the one or more optical lenses and configured to control the refractive power value of a second refraction area thereof.

Myopia or nearsightedness of an eye is characterized by the fact that the eye focuses distant objects in front of its retina. Myopia is usually corrected using a negative lens and hyperopia is usually corrected using a positive lens.

Myopia is developed for example when the axial growth of the eye is disproportional or does not correspond to the development of the lens of the eve. An increased axial length of the eye entails that the retina of the eye lies at an increased distance from the lens and pupil of the eye.

When the axial length of the eye does not match the refractive power of the lens of the eye, the light entering the eye is focused before the retina. In other words, the retina lies at an axial distance from the lens behind the plane where incoming light is focused.

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 was predicted to be 2.6 billion globally, which is expected to rise to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide, and in Europe.

Pathology such as myopic maculopathy and optic neuropathy in highly myopic eyes can cause significant irreversible visual impairment and blindness. Besides, myopia increases the risk of other pathological ocular changes such as cataract, glaucoma, and retinal detachment, all of which can cause irreversible vision loss. Significant disease associations exist even at low and moderate levels of myopia. Current evidence suggests that there is no safe threshold level of myopia for any of the known ocular diseases linked to myopia.

The importance of the increase in the prevalence of myopia and its sequelae has been well documented particularly in East Asian countries that have experienced the most pronounced increase in myopia prevalence. Consequently, the experience in preventing the development and progression of myopia in children and adolescents is more advanced in East Asia. The prevalence of myopia also increased in Europe in recent decades and reached the level of 45-50% in the 25-

29 years old age group. Thus, Europe is becoming aware of the importance of myopia both as a public health issue and as a significant socioeconomic burden.

Myopia, especially the increasing prevalence, seems to be a result of our changing lifestyle in the last few decades. Among other factors, increased time spent indoors seems to stimulate the axial growth of children’s eyes, thereby inducing myopia. Myopia onset and progression is now understood to result from a complex interplay of visual/environmental conditions and genetic factors that modulate the visually guided eye growth. As a result, the control mechanisms are no longer able to coordinate growth with the development of the optical components of the eye.

As a result, myopia prevention, or the deceleration of myopia progression, has been a key research topic within the ophthalmic scientific community. Today, proven measures include pharmacological solutions, orthokeratology, multifocal contact lenses or spectacles with an aspheric or discrete dual-focus design.

Studies show that increasing the amount of time spent outdoors decreased the incidence of myopia in children. The underlying reasons why increased time spent outdoors is linked to a lower myopia incidence have not completely been elucidated so far, but proposed reasons include factors such as higher light intensities, variations in the chromatic light composition, differences in dioptric topographies, less near work, and a decrease in the accommodative demand.

In recent developments, interventions to prevent the progression of myopia have been studied and developed. Studies including children wearing progressive addition lenses as compared to children wearing single-vision lenses suggested an advantage of a peripheral myopic defocus.

Induction of peripheral myopic defocus has consequently become the mainstay of a number of current myopia control strategies.

The optical measures for preventing myopia include wearing of defocus incorporated multiple segments (DIMS) spectacle lenses, the application of concentric zone dual-focus soft contact lenses that provide simultaneous correction and myopic defocus, or the use of orthokeratology contact lenses (also known as ortho-k contact lenses).

Spectacles with discrete dual-focus designs typically have a small (e.g. 7-9 mm) central zone with a conventional spherical correction providing a clear vision for the patient when looking through this zone. Beyond this zone, towards the periphery, an array of lens units (microlenses) with varying designs and distribution is present. The aim of these lens units is to focus the incoming light in front of the retina. It has been shown that wearing these dual-focus designs consistently throughout the day and over an extended period of many years during a child’s period of growth, can slow down or even halt the progression of myopia.

Existing myopia control lenses may be able to slow down the progression of myopia but have a static response that cannot be changed according to any of the wearer's anatomical parameters or environmental conditions.

Regardless of the specific design and intended effect of such lens units, they induce a static effect and are the result of a trade-off between a target treatment and acceptable remaining visual acuity when looking through the areas comprising lens units. For example, while one could consider increasing the spherical power of the lens units to further slowdown myopia progression, such an increased power would negatively affect the visual acuity. As a result, there could be poor therapy adherence. or increased risk of falling or accidents due to the low peripheral visual acuity.

Next to this, it should be noted that the size of the pupil of the wearer can vary under various illumination conditions (e.g. outside in full daylight or inside in a dark room) and this affects the area which is exposed to the lens units peripheral blur or the intensity of their response.

However, this correlation is not controlled and may vary between different patients. On top of that, as the lens unit designs are fixed and typically based on a specific eye model with fixed dimensions, they are not customized to the individual anatomical parameters (e.g. axial length) of the patient, both at the start of the treatment as throughout it. Hence, the lack of customization bears the risk of a subpar treatment effect.

The present disclosure aims at solving at least one of the disadvantages mentioned above.

There is also a need for an optical lens (intended to be used in spectacles or contact lenses) wherein the progress or creation of myopia can be reduced in a more versatile, adaptable and/or effective manner.

According to a first aspect, the present disclosure provides an optical lens, for example a spectacle lens, intended to be carried in front of an eye of a user, the optical lens comprising: a first refraction area having a first refractive power configured to focus an image on the retina of the eye of the user; a second refraction area having a second refractive power different from the first refractive power, and being configured to focusing the image on a position in front of or behind the retina of the eye of the user; wherein the refractive power of at least a portion of the second refraction area of the optical lens is tunable.

In case the optical lens is a myopia control lens, the first refraction area is usually arranged to provide visual acuity to the user, while the second refraction area is arranged so as to provide a reduced development of myopia for the user or at least a slow-down of the progression of abnormal refraction of the eye, for instance caused by myopia. Advantageously, the first refraction area may be arranged in a central zone of the optical lens for providing a corrected, clear vision for the user when looking through the central zone, while the second refraction area may be arranged beyond the central zone, more specifically a zone arranged in peripheral direction beyond the central zone, for instance an annular part of the lens directly around the central zone of the optical lens, for providing an over-corrected or under-corrected vision for the user (in order to reduce the progression of myopia, for instance).

The tunability of the refractive power of the second refraction area may be used to improve the comfort of the optical lens as well as their clinical effect. Furthermore, the optical lens makes it possible to take into account one or more physical properties of the user (which may vary in time as the user is getting older) and/or one or more environmental or ambient conditions of the user, for instance the brightness of the artificial and/or ambient light around the user, the orientation of the head of the user (for instance an orientation representative of book reading or an orientation representative of television watching. This may all help in reducing the (progression of} myopia of the user.

For instance, when the refractive power of at least a portion of the second refraction area of the optical lens is tunable, one could adapt the power according to the specific situation or surrounding conditions. For example, it is possible to tailor the power & power distribution to the wearer’ s anatomical parameters (e.g. axial length). Furthermore, when a bright and/or outdoors environment is detected, the power could be reduced to improve the visual acuity for far vision gazing. Or, when a dark or indoor environment is detected, the power could be increased to enhance the treatment effect. In combination, or in another embodiment, when a reading or near activity is detected, the power could be increased to enhance the treatment effect.

By configuring the optical lens to comprise an area with tunable refractive power, the effect of the optical lens can be tuned in time. The effect of this optical lens and device therefore is not static. As mentioned above, tuning could be used to accommodate personal needs, parameters, or preferences of the user which may vary in time. The customization could result in higher treatment quality and better treatment effect.

In embodiments of the present disclosure, the second refraction area of the optical lens comprises a set of tunable lens units. In these embodiments, each of the tunable lens units may comprise a lens portion having a variable refractive power value that is tunable or tuned by an electronic controller connected to the tunable lens unit. The optical lens is preferably configured to allow a first subset of the tunable lens units to be tuned independently from a second subset of the tunable lens units. The first subset may comprise any number of lens units, the second subset may also comprise any number of lens units, the number of lens units of the first subset may or may not be equal to the number of the second subset.

In embodiments of the present disclosure the optical lens comprises a transparent lens element. The transparent lens element can be made of any suitable transparent material. The transparent lens element can be comprised of one single transparent substrate or two or more transparent substrates stacked on each other. Lens units may be arranged in the interior of the lens element, for instance embedded in a single substrate or between two stacked substrates, and/or on top of outer surface of the lens element, i.e. on its top surface and/or bottom surface). Furthermore, the substrate may be configured to provide a base refractive power (which may or may not be equal to zero, for instance depending on the eye prescription for the user). On top of this base refractive power the lens units may provide an additional refractive power, which may be variable 5 or fixed. For instance, in the above-mentioned second refraction area that has tunable second refractive power, the second refractive power is the superposition of the base refractive power of the substrate(s) and the variable refractive power provided by the one or more lens units.

The tunable lens units may be arranged in various patterns on or in the optical lens. For instance, in some embodiments, the plurality of lens units is arranged in a honeycomb pattern. In other embodiments the lens units are arranged in a pattern of one or more concentric rings.

Furthermore, while in some embodiments all lens units are of the tunable type, in other embodiments some of the lens units are of a tunable type and other lens units are of a static type (the static type may be subdivided into a fixed type with a refractive power than cannot be tuned and a type wherein the lens unit as such may be tunable but is not tuned). Embodiments wherein tunable lens units are combined with static lens units at corresponding positions on or in the lens are possible as well. This guarantees a minimum optical power is always present at the desired locations, regardless of the power of the tunable lens units.

As defined herein the word “tuning” of a tunable lens unit may involve increasing or decreasing the refractive power of the lens unit, for instance between a high refraction power value and a low refraction power value (for instance all the way down to no/zero refraction power). The increasing or decreasing may be accomplished in a stepwise manner or in a continuous manner, as will be explained later.

As mentioned above, different refraction areas may be created in the optical lens by lens units. These lens units may typically be small-sized lens units. These small-sized lens units are sometimes referred to as lens units or lens units. A small-sized lens unit may have a diameter typically ranging between 0.5 mm and 1.1 mm. However, in other embodiments the lens units are (considerably) larger.

The second refraction area may have various shapes. In an embodiment of the present disclosure the second refraction area has an annular shape surrounding a central area of the optical lens, while in other embodiments only one or more segments of the annular shape forms the second refraction area.

The second refraction area may comprise one or more tunable lens units defining a variable refractive power value and one or more static lens units defining a fixed refractive power value. For instance, in certain embodiments all lens units in the second refraction area may be of the tunable type, but in other embodiments only one or more of the lens units are of the tunable type while the other lens units are static lens units, i.e. lens units having a fixed refractive power value. A static lens unit may be formed by tunable lens units that are not controlled at all or are indeed controlled but controlled in such a way so as to keep the refractive power value of the lens units essentially constant. Additionally or alternatively a static lens unit may be a fixed lens unit, i.e. a lens unit without a lens portion of which the refractive power may be varied (and only with lens portions having a fixed refractive power, such as in conventional spectacles or contact lenses).

In embodiments of the present disclosure the optical lens comprises one or more tunable lens units configured to allow varying of their respective refractive power values by the electronic controller when the optical lens is in use. The term “in use” herein may denote that the tuning may be performed after the optical lens including the lens units has been manufactured, for instance when the optical lens is worn by the user or right before/after the optical lens is worn by the user, for instance during a visit to an optometrist. For instance, the user may be requested to periodically visit an optometrist or ophthalmologist (for instance once a year) in order to set the refractive power of the optical lens or the refractive powers of different portions of the optical lens at the required refractions power value(s). In other situations, the refractive power of the optical lens or the refractive powers of portions of the optical lens may be set at the required value(s) when the user is wearing the optical lens (spectacle).

In an exemplifying embodiment, a tunable lens unit is electrically connected to the electronic controller, the controller being configured to select one or more values of the second refractive power for the lens unit from a range of second refractive power values, the range of second refractive power values being defined by a relatively high, first refractive power value and a relatively low, second refractive power value. In some of these embodiments the controller and the tunable lens units are configured to select refractive power values of a tunable lens unit from at least two, preferably three or more different discrete refractive power values. For instance, the refractive power value me be selected to correspond to ON and OFF (two levels), correspond to a low, medium, and high level (i.e. three levels), or correspond to any of four or more levels. In other embodiments the controller and the tunable lens units are configured to select refractive power values in a continuous range between the first and second refractive power values. The refractive power in these embodiments may be varied continuously and is not restricted to a plurality of discrete values. For instance, the refractive power values of the one or more lens units in the second area may be caused by the electronic controller to vary at will between the minimum refractive power value and maximum refractive power value. When in the present disclosure the controller is described as being configured to perform an operation, the controller may have specifically designed hardware enabling the operation to be performed. Alternatively, or additionally, the term may define that the controller is a programmable electronic controller which may be programmed or is loaded with a suitable computer program (software) to enable the operation to be performed.

In embodiments of the present disclosure the electronic controller is configured to vary the refractive power value of one or more of the tunable lens units in the second refraction area. The controller may further be configured to maintain a substantially constant refractive power value of one or more other lens units in the second refraction area. The latter lens units then (temporarily) function as static lens units. For instance, when the controller is connected to a sensor for eye tracking (herein also referred to as gaze tracking or gaze sensing), the controller may tune only the lens units that are at the location of the line of sight of the eye to have a reduced or zero power while keeping the remaining tunable lens units at a constant refraction power value thereby improving the visual acuity while keeping the treatment effect (by the other lens unit of which the power has not been tuned to a reduced or zero power).

In embodiments of the present disclosure the optical lens is configured so that a plurality of lens units is collectively tunable. In other embodiments of the present disclosure the optical lens is configured so that a plurality of lens units is individually tunable, while in still other embodiments the optical lens is configured so that a first subset of (a set of a) plurality of lens units is collectively tunable, a second subset of (a set of a) plurality of lens units is collectively tunable, wherein the lens units of the first subset are tunable independently from the lens units of the second subset.

The optical lens may be configured to allow tuning of the optical refractive power of said portion of the second refraction area based on an external electrical signal. The external electrical signal may be of various origins. For example, the external electrical signal may be a clock signal from a clock, a switch on / switch off signal from a manual switch, and/or a sensor signal from a sensor. The sensor may be connected with a wired and/or wireless connection with the optical element, for instance with the electronic controller of the optical lens. In embodiments of the present disclosure, the electronic controller is configured to control the tuning of the optical refractive power of one or more tunable lens units based on an external signal received by the electronic controller. The external electrical signal is a sensor signal received directly or indirectly from one or more internal or external sensors.

For instance, a sensor may be configured to determine an environmental condition, such as the brightness of ambient light. In an embodiment of the present disclosure the sensor is configured to detect if the user is in an environment with a high brightness, for instance outdoors. As long as the user is in a bright environment there is no need or less so to have a peripheral blurring lens for preventing the progression of myopia. Therefore, at these conditions the controller may determine to control the tunable lens units to reduce the refractive power of the secondary area. This reduction may also improve the visual acuity for far vision gazing.

Another example of a sensor is a proximity sensor. A proximity sensor is a sensor that is configured to sense the proximity of an object to the optical lens, for instance a book, a display (of a tablet or telephone). Such sensor may be attached to the frame of the optical device or may be integrated with the optical lens. When the optical device is a pair of glasses, the sensor may be attached to the frame thereof so that movement of the head of the user results in a corresponding movement of the sensor.

If the object is at close proximity, for instance when the user is reading a book, the tunable lens units may be tuned to a higher refractive power value, whereas when such object is not detected. the refractive power value be selectively tuned to a lower value. For similar purposes the sensor may be an orientation sensor configured to sense the orientation of the lens element relative to the force of gravity. From this orientation of the optical lens and therefore the orientation of the head of the user, the controller may determine whether or not the head of the user is in a reading orientation. Depending on the outcome the controller may control the lens units to change their refractive power value. In further embodiments the proximity sensor and orientation sensor may be combined or at least the electrical signals from both the proximity sensor and the orientation sensor may together be used by the controller to determine whether or not the refractive power values of lens units need to be tuned.

In exemplifying embodiments, the electrical signal from a sensor is the electrical signal received from a sensor provided in an external wearable device, such as a smartphone. The electrical sensor signal in these embodiments is transmitted wirelessly to a wireless signal receiver (for instance a Bluetooth receiver) connected to or integrated with the controller. The wireless signal receiver is considered to form part of the sensor (the remainder of the sensor being provided in the electronic device).

In exemplifying embodiments, the electrical signal from a sensor is the electrical signal that is received by the controller from an external electronic device, for instance a wearable device, such as smart phone, tablet or smart watch, or a digital screen, which electrical signal is representative for the current and/or past activity of the user as determined by the external electronic device itself. As an example of such an electrical signal a communication signal from the electronic device. In these exemplifying embodiments use may be made of the vast amount of useful data that is created, collected and/or made available by modern day smart technology, including the one integrated in the frame. For example, there could be a learning algorithm in the electronic controller, for instance an electronic controller in the frame. configured (for instance programmed) to adjust the response to the user's personal response or behavior.

In another exemplifying embodiment the sensor and/or the controller is configured to determine the direction of the gaze of the user. When the user gazes in a direction straight ahead and looks for instance through a central (first) area of the optical lens, the lens units in the (second) area surrounding the central area may have an increased refractive power so as to provide the myopia control treatment as discussed herein. The central (first) area or zone of the optical lens in this case does not comprise any lens unit or has tunable lens units that are tuned to have an essentially zero refractive power value. As soon as the user starts gazing in another direction (relative to the optical element and therefore relative to the head of the user), the line of sight of the eye of the user may cross the (second) area surrounding the central area so that visual acuity may be reduced in case the tunable lens units in this area were to be controlled to have a high refractive power value. In this situation the controller may determine that in a subregion of the (second) area surrounding the central (first) area the tunable lens units should be controlled to have a low refractive power value rather than the above-mentioned high refractive power value. Additionally, in embodiments wherein also a central zone of the optical lens comprises tunable lens units, these lens units may be temporarily tuned to a relatively high refraction value, as long as the user keeps gazing through the circumferential area.

The electronic controller is configured to control the one or more tunable lens units to adapt their respective refractive powers according to at least one of a: - a first control signal received by the electronic controller and representative of the brightness and/or darkness of the environment of the user; - a second control signal received by the electronic controller and representative of the current activity of the user, for instance by increasing the refractive power value when reading or near activity is detected; - a third control signal received by the electronic controller and representative of the lens unit direction of the gaze of the user.

In an embodiment of the present disclosure tunable lens units are used in a first region of the second refraction area of the optical lens, which first region is oval shaped and offset downward with respect to the optical center of the lens, and/or static lens units are used in a second region of the second refraction area of the optical lens. The second region may or may not partially overlap the first region.

As mentioned earlier, the lens units of an optical lens may be of the tunable type and/or of the static type. The optical lens may comprise one or more ring-shaped concentric areas wherein a combination of tunable and static lens units is arranged. The ring-shaped area can overlap with one or more rings of lens units or can be formed in a honeycomb pattern. In one or more of the ring- shaped areas tunable lens units and static lens units may be alternated. Alternatively or additionally, a first ring-shaped area only has tunable lens units while in a second ring-shaped area (different from the first ring-shaped area) the optical lens only has static lens units.

In still further embodiments tunable lens units are combined with static lens units only in certain directions or quadrants, preferably in predominantly horizontal directions. In certain embodiments one or more static lens units are combined with one or more tunable lens units by placing them behind each other. The tunable lens unit may be arranged as separate elements on top of (the substrate of) the lens or may be integrally formed therewith. Alternatively or additionally, tunable lens units are embedded within the (substrate of) the lens.

In embodiments of the present disclosure a tunable lens unit is configured to change its refractive power for light of a first polarization direction and to keep its refractive power substantially of fully unchanged for light of a second polarization direction, orthogonal to the first polarization direction. These embodiments provide in fact an optical lens with two different focal lengths. A dual response for in principle each position of the lens (substrate) is created.

Next a few embodiments of the lens units of the tunable type are described.

According to embodiments of the present disclosure one single lens unit or a plurality of lens units may form a so-called cell or lens cell. A tunable lens cell may be provided in various types of cells. Some types of cells comprise liquid crystal material (i.e. LC material), other cells are based on electrowetting implementations to make (lens unit of) the lens cell tunable.

The tunable cell may comprise: - a first transparent substrate; - a second transparent substrate; - a first transparent electrode arranged on the first transparent substrate; - a second transparent electrode arranged on the second transparent substrate; - a connection element between the first and second transparent substrate, the connection element configured to define a closed space between the first electrode on the first substrate and a second electrode on the second substrate, wherein the closed space is filled with liquid crystal (LC) material; - one or more control lines connected to the electronic controller and the first and second transparent electrodes; wherein the electronic controller is configured to control the orientation of the LC material in the closed space by applying a control signal to the first and second transparent electrodes.

Examples of tunable optical cells are described in documents WO 2017/211899 Al and WO 2022/090223 A1, both documents being in the name of the same Applicant. The content of both documents is considered to be incorporated in the present disclosure.

The LC material may be configured to function as an isotropic material of which the refractive index can be changed in the visual part of the spectrum (i.e. visual to the user) when applying an electrical field caused by applying an electric control signal (i.e. a suitable voltage signal) from the electronic controller on the first and second electrodes.

Additionally, the optical lens may comprise means for setting a desired profile of liquid crystal pretilt angles over the inner side of the closed space. In embodiments of the present disclosure, the optical lens comprises an alignment layer facing the closed space, the alignment layer preferably being configured to create a desired profile of liquid crystal pretilt angles varying across the alignment layer. Additionally or alternatively, at least one of the first transparent electrode layer and the second transparent electrode layer is configured to create a desired profile of liquid crystal pretilt angles varying across the associated transparent electrode layer, wherein the at least one of the first transparent electrode layer and the second transparent electrode layer preferably is a patterned conductive layer. The patterned conductive layer enables the electronic controller to apply different voltage levels at different positions across the side(s) of the cell facing the closed space so that a suitable (non-constant) profile of liquid crystal pretilt angles may be provided. In embodiments of the present disclosure a lens-shaped structure is absent in the closed space. In other embodiments, however, the optical lens comprises such a lens-shaped structure, for instance a (part of a) diffraction element, more specifically a Fresnel type of diffraction element, arranged between the first and second transparent substrates, preferably arranged inside the closed space.

The liquid crystal (LC) material may be a nematic liquid crystal material having its long axis aligned in one preferred linear direction. A nematic liquid crystal material is an anisotropic material, having a preferred alignment direction. In case of incoming light having different orthogonal polarization directions, a stack of two lens cells, with their optical axis arranged orthogonally relative to each other, is needed to cope with the orthogonal polarization directions of the incoming light. For instance, in embodiments of the present disclosure, the optical lens comprises a first lens unit having a first alignment direction and a second lens unit having a second alignment direction, wherein the first lens unit is positioned on top of the second lens unit while the first alignment direction is orthogonal to the second alignment direction.

The liquid crystal (LC) material may be a cholesteric liquid crystal material. The cholesteric liquid material provides a helical pitch so as to function as an isotropic material of which the refractive index can be changed in the visual part of the spectrum when applying an electrical field. In some embodiments wherein cholesteric liquid crystal material is used, the material is isotropic so that no stacking of cells is needed to cope with the incoming light.

Next a few embodiments of the distribution of the tuned refractive power over the lens region are described.

In an embodiment the refractive power values of the individual lens units increases as the radial distance from the lens unit to the optical center of the optical lens increases.

In an embodiment wherein the optical element comprises one or more static lens units, the static lens unit is a non-controlled tunable lens unit. The term “non-controlled”’ : for instance not connected to the electronic controller or connected to the electronic controller but the electronic controller is configured to keep the refractive power constant In another embodiment the static lens unit is a fixed lens unit, preferably a lens unit without a lens portion of which the refractive power is variable.

The refractive power of the tunable lens units might be varied in time. In embodiments of the present disclosure the optical lens, for instance the electronic controller in combination with the lens units, is configured to vary in time the refractive power value of a lens unit. The optical lens may be configured to change the refractive power value by at least 20% within 1 second. The percentage of change of the refractive power could also be higher in an embodiment of the present disclosure. In use, a response time of 1 second for the tuning of the lenses can be enough. When the variation of the refractive power depends on the gaze direction of the user, a response time of 50ms is desired.

Furthermore, the variation frequency of the refractive power value preferably is larger than 50 Hz, preferably lager than 100 Hz. With such high frequencies flickering may be avoided or reduced and/or the user experiences an averaged focal length.

According to another aspect an assembly of one or more optical lenses as defined herein and a controller connected to the one or more optical lenses and configured to control the refractive power value of the second refraction area, is provided.

Controlling the refractive power value of the second refraction area preferably comprises tuning the refractive power value or refractive power values of one or more tunable lens units arranged in the second refraction area.

According to a preferred embodiment the assembly comprises one or more sensors configured to sense one or more ambient/external conditions and to provide a sensor signal representative of the sensed condition, wherein the controller is configured to control the refractive power value of the second refraction area of the lens element based on the sensor signal received from the sensor.

The above and/or other aspects of exemplary embodiments will become apparent and more readily appreciated from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying figures of which:

Figure 1 shows a schematic drawing of user 200 wearing an optical device 100.

Figure 2A shows a schematic top view of an embodiment of an optical lens 1.

Figure 2B shows a cross-section along lines A-A of figure 2A.

Figure 3A and 3B show possible arrangement of lens units 10 schematically.

Figure 4A is a top view (left-hand side) and a cross-section (right-hand side) of a tunable lens unit;

Figure 4B is a top view (left-hand side) and a cross-section (right-hand side) of a static lens unit;

Figure 4C is a top view (left-hand side) and a cross-section (right-hand side) of a lens unit that either may be tunable or static;

Figure 5 shows a schematic drawing of a cross-section of the optical lens 1, comprising an embodiment of tunable lens units and static lens units.

Figures 6A and 6B are schematic top views of embodiments of an optical element including respectively one ring-shaped single tunable lens cell and three concentric ring-shaped single tunable cells, wherein each of the tunable cells are divided into one or more individual lens units;

Figures 7A-7D are schematic top views of embodiments of tunable lens units 14 and static lens units 16 combined in the optical lens 1, wherein different distributions of tunable and static lens units overt the (second refractive area 5 of the) optical lens 1 are shown.

Figures 8A-8B show schematically components arranged in the optical lens that enable the tunable lens units of the optical lens to be controlled by one or more controllers.

Figures 9A-9E show schematic drawings of possible embodiments comprising tunable lens units connected to a controller and a sensor.

Figures 10A-10B show schematic drawings of possible embodiments comprising tunable lens units in the central aera of the optical lens.

Figure 11A is a top view of a further embodiment of an optical lens, wherein the tunable lens units are tuned to provide a gradient in the refractive power profile across the radial direction of the optical lens, while figure 11B is a graph showing the local power of the optical lens as function of the radial distance (R) relative to the center of the central area.

Figures 12A-12B 11B show schematic drawings of possible embodiments comprising tunable lens units with a gradient in the refractive power profile across the optical lens.

Figures 13A-13C show schematic drawings of possible embodiments comprising a mixture of static and tunable lens units and a controller and a sensor.

Figures 14A-14B are schematic cross-sections of a further embodiment of a tunable lens unit

Figure 15 is a schematic side view of an optical lens showing two orthogonal polarizations (E Es).

Figure 16A is a schematic top view of a further embodiment of a lens unit, while figure 16B a graph representing the optical power (D) of two different polarizations (Ex, Ey) as function of an angle (6) of the embodiment of figure 16A is depicted;

Figures 17A-17C are schematic cross-sections of a further embodiment of a tunable lens unit.

Figures 18A-18C are schematic cross-sections of a further embodiment of a tunable lens unit.

Figures 19A-19C are schematic top views of further embodiments of an optical lens.

Where herein a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Certain ranges are presented herein with numerical values being preceded by the term "about." The term "about" is used herein to provide literal support for the exact number that it precedes, as well as a number that is near to or approximately the number that the term precedes. In determining whether a number is near to or approximately a specifically recited number, the near or approximating unrecited number may be a number which, in the context in which it is presented, provides the substantial equivalent of the specifically recited number.

It is noted that, as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

Figure 1 shows a user 200 wearing an optical device 100, in this case a pair of spectacles, comprising two optical lenses 1 according to the present disclosure. The optical device 100 (for instance, the frame of a pair of glasses) can have any shape or form. Furthermore, the optical lens 1 to be mounted into the optical device 100 may have any shape after manufacturing. Upon preparation, the optical lens 1 is cut according to the specifications of the user and the optical device. Generally, the optical lens 1 is cut upon preparation into a predetermined shape to fit into the device 100 of the user 200, as will be explained hereafter.

Figures 2A and 2B show a schematie, more detailed view of the embodiment of the optical lens 1 in accordance with figure 1. Note that the exact frame shape of the optical device will typically not be known upfront, meaning the overall optical lens 1 will need to be prepared in a standard size (e.g. 65mm round shape). Once the shape is known (selected by a patient), as well as the fitting parameters (e.g. pupillary distance and fitting height) of the wearer have been determined, the outline of the frame and its position with respect to the optical center of the lens can be fixed. However, this means the shape could arbitrarily cut the lens units in any given area.

In figure 2A, the outline of the optical lens 1 is rectangular in the schematic drawing. In reality, the optical lens 1 could have any shape of outline after manufacturing. (The standard preparation is a 65mm round shape.) Upon preparation, the optical lens 1 is cut to fit the frame shape of the optical device 100. An imaginary cutting line 31 is indicated in figure 2A. Obviously, the shape of the cutting line 31 may vary depending on the frame shape.

The optical lens 1 of figures 2A and 2B comprises a transparent lens element 24, The transparent lens element 24 has a rectangular outline in the drawing and is cut into a final shape to properly fit the frame of the optical device 100.

The transparent lens element 24 can be made of any suitable transparent material, like glass, polycarbonate, or other plastic material such as Trivex. Furthermore, the transparent lens element 24 can be comprised of one single transparent substrate 25, although in other embodiments the lens element 24 comprises two or more stacked transparent substrates 25 (the interface between such transparent substrates being schematically indicated with a dashed line 29 in figure 2B, the embodiment of figure 29 comprising two stacked substrates 25).

Figures 2A and 2B further show a number of lens units 2 that have been integrally formed with or attached to the transparent lens element 24. More generally, lens units 2 can be arranged in the interior of the lens element 24, for instance inside a substrate or between stacked substrates (as is shown in figure 5) and/or on top of the lens element 24, i.e. on top of any of the substrates 25 (i.e. on the top side or bottom side, see for instance figures 2A, 2B and 5). In the shown embodiment the lens units 2 constitute a honeycomb or honeycomb-like structure comprising a large number of lens units 10 (herein also referred to as lenslets 10).

More generally, the lens element 24 is configured to provide a base refractive power (which may or may not be equal to zero, for instance depending on the eye prescription for the user). On top of this base refractive power the lens units 2 may provide an additional refractive power, which may be variable (tunable) or fixed. For instance, in the above-mentioned second refraction area that has tunable second refractive power, the second refractive power is the superposition of the base refractive power of the substrate(s) and the variable refractive power provided by the one or more lens units 2.

In the embodiment shown in figures 2A and 2B the optical lens 1 comprises a first refraction area 6 comprised of a central area or central zone 12 and a second refraction area 5 essentially surrounding the central zone or area. The first refraction area is formed to have a first refractive power. In most preferred embodiments, this refraction area is configured to focus the image on the retina. The second refraction area has a second refractive power different from the first refractive power and is configured to focus the image on a position in front of or behind the retina of the eye of the user. To provide in the second refraction area 5 a refractive power different from the first refractive power, the transparent element 24 in the second refraction area 5 comprises one or more of the earlier-mentioned lens units 2. In the embodiment of figures 2A and 2B the lens units 2 are formed as lens units 10.

In the embodiment shown in figures 2A and 2B the second retraction area 5 formed by a number of lens units 2 that have been arranged as a honeycomb or honeycomb-like structure. In other embodiments, for instance the embodiment shown in figures 3A and 3B, the second refraction area 5 is also formed by a large number of lens units 2, but these lens units are arranged ina plurality of imaginary concentric rings 11'-11% The number of rings in figures 3A and 3B is four, but this number can be smaller (three, two or one) or larger (five, six, seven, etc.).

More specifically, figure 3A shows a cylindrical arrangement of lens units 10 forming the lens units 2. The lens anits 10 may form circular rings as is shown in figure B, but other shapes are possible as well. Examples of other shapes are concentric oval rings or concentric polygonal rings (cf. the hexagonal rings of figure 3B). The number of lens units 10 in the optical lens 1 can vary.

One ring can consist of more lens units or micro lenses than indicated in the schematic drawings.

As mentioned earlier, the optical lens in an embodiment can comprise more rings of lens units, or less, than in the schematic drawings.

In embodiments shown in figures 2A, 2B, 3A and 3B the central area 12 of the optical lens does not comprise (is free from) lens units 2. Furthermore, the central area 12 preferably has a first refractive power configured to focus an image on the retina of the eye of the user. Most preferably, the refractive power of the optical lens corresponds to the user's optical aberration to be corrected, i.e. the prescription associated with the particular user. Therefore, the center area 12 of the optical lens, at least in these embodiments, does not provide additional refractive power and also does not comprise lens units. However, embodiments wherein lens units 2 are incorporated in the central area 12 of the optical lens are possible as well. These embodiments will be discussed further, for instance with reference to figures 10A and 10B. Furthermore, in the embodiments shown thus far the lens units 2 in the second refraction area 5 are distributed evenly over the transparent lens element 24. In other embodiments the lens units may have been distributed unevenly over the lens element 24, thereby creating areas where the density of lens units is higher and other areas where the density is lower.

An advantage of using an even distribution of lens units, for example rings or a honeycomb structure, is that the optical effect of the optical lens 1 tends to be symmetric with respect to the center of the lens. By using hexagonal rings for example, the micro lenses can be arranged side by side. This enables the adjustment of the effect of the optical lens according to almost any preference since the lens units cover the complete area of the second refractive area.

Furthermore, a symmetric distribution of lens units may be more practical for manufacturing and preparing the optical lens. An uneven distribution of lens unit could be advantageous if one prefers the effect of the optical lens to be uneven. For example, if the upper section of the periphery of the image is preferably more out of focus, the lens units could be arranged accordingly in these sections of the optical lens. However, an unevenly distributed effect of the optical lens can also be realized by using an embodiment wherein the arrangement of lens units in the optical lens is symmetrical or even. For example, lens units of different or tunable refractive power can be employed.

The size of the optical lens 1, more specifically the (substrate(s) of the) lens element 24, is preferably such that it can be easily accommodated in a pair of glasses 100 (after having been cut in the required shape, see the imaginary cutting line 31 of figure 2A) so that it can be worn at a predetermined distance in front of an eye of the user 200. Thus, the optical lens size is generally in the order of magnitude of square centimeters. The optical lens is configured to correct any aberrations in the focus of the eye of the user. The refractive power of the fist area is most preferably determined by the refractive power of the (substrate(s) 25 of the) transparent lens element 24 of the optical lens itself.

The refractive power of the second refractive area is determined by the combination of the refractive power of the transparent lens element 24 and the lens units incorporated in or on the lens.

The refractive power of the optical lens and the lens units embedded in the lens combined result in the second refractive power, the refractive power of the second refractive area.

In preferred embodiments (cf. figures 2A, 2B, 3A, 3B), the lens units are only incorporated in a region or zone around a central zone or central are 12 in the center of the transparent lens element 24. Usually, the optical lens 1 is manufactured without prior knowledge about the final shape of the optical lens, which depends on the users’ preferences and on the shape and size of the spectacle frame. Thus, to avoid a large amount of lens units being cut off during preparation and mounting into the frame (so that part of the lens units is wasted), the area where lens units 2 are incorporated in or on the transparent lens element 24 can be confined to an area around the central zone. However, the lens units might be incorporated also in the periphery of the transparent lens element.

Different types of lens units 2 can be used in the optical lens. Two generic types of lens units are used in the embodiments disclosed presently: static lens units 16 and tunable lens units 14.

Figure 4A and 4B are schematic drawings of two types of lens units: tunable and static.

Static lens units have a static effect; the refractive power of these lens units does not change.

Tunable lens units can have a varying effect: the refractive power of these lens units can be changed, for instance by applying a suitable voltage to the lens units. The two types of lens units are differentiated with schematic shading.

Figure 4A shows a schematic drawing of a tunable lens unit 14, which is indicated with striped hatching in the lens unit. Figure 4B shows a schematic drawing of a static lens unit 16, which is indicated with solid shading. Both figures show a schematic drawing of the top view and side view of the lens units. The shape the lens unit used in an embodiment might differ from the shape of the lens units in these figures. These drawings give an indication of the possible shape of the lens units, and mainly function to show the different shadings used to indicate the different types of lens units used in the schematic drawings that follow. Throughout the disclosure, these shadings will be used to indicate tunable and static lens units. When no shading is added to a lens unit in a figure (cf. lens unit 18 in figure 4C), this means that the lens unit could be of any type (i.e. either tunable or static).

By using tunable lens units in the optical lens, the refractive power of an area of the optical lens can be tuned. In this case, the effect of the optical lens is no longer static, and can be adjusted according to the user. For example, the tunable lens units allow the optical lens to be customized to the individual anatomical parameters of the user. By personalizing the refractive power of the tunable lens units according to the user, the tradeoff between visual acuity and medical effect can be personalized. Furthermore, the tunable lenses could be controlled via a controller to adjust the refractive power provided according to the situation or condition and the corresponding needs of the user.

Tunable lens units may for example use liquid crystal material or electrowetting techniques to tune the refractive power. Note that any increase or decrease could range between a high power value and all the way down to no power or zero residual power.

In most preferred embodiments both tunable lens units 14 and static lens units 16 are applied in combination in the optic lens. One way in which the different types of lens units can be combined is shown in figure 5.

Figure 5 shows a schematic drawing of the cross section of a part of an optical lens 1. The figure shows a transparent substrate provided with two transparent lens static units 16 and two transparent tunable lens units 14. The static lens units 16 are arranged on top of the substrate of the optical lens 1 (wherein the static lens units are integrally formed with the substrate), while the tunable lens units 14 are embedded in the substrate (or in fact sandwiched between two separate substrate portions that have been stacked on each other). An advantage of combining different types of lens units in such a way, is that they can overlap. Furthermore, by arranging the different types of lens units on different levels in the optical lens, manufacturing the optical lens is easier.

Furthermore, while the static lens unit 16 may be integrally formed with the transparent substrate, in other embodiments the static lens unit 16 is a separate unit of the tunable type which however is not connected to an electronic controller and therefore cannot be tuned when the optical lens is in operation (i.e. the lens unit is tunable, but not tuned).

Tunable lens units 14 and static lens units 16 can be combined in alternative manners as well. For example, all lens units 14, 16 could be embedded inside the substrate of the optical lens, or all tunable lens units 14, 16 could be arranged on top of the substrate of the optical lens.

In embodiments of the present disclosure, the second refraction area 5 is provided by applying a large number of lens units, preferably of the lens unit type. The area 5 comprising the lens units has a refractive power that is determined by the refractive power of the substrate of the optical lens and the tunable/static lens units 14, 16 combined. Because of this, the refractive power of the second refraction area 5 is different from the refractive power of the first refraction area 6 that oftentimes is free from static/tunable lens units 14, 16. In this way, a first and a second refractive area 5,6, having different refractive powers, can be created in the optical lens. When at least a part of the lens units is tunable, the refractive power of that area will be tunable too.

In embodiments of the present disclosure the optical lens comprises one or more tunable cells wherein each tunable cell comprises one single lens unit or a plurality of lens units. For instance, in the embodiments of figure 3A and 3V, each ring of lens units may be formed by a separate tunable cell. Each tunable cell can be controlled individually via the electronic controller, i.e. independently from the other tunable cells. In other embodiments, each tunable lens unit of each tunable cell can be controlled individually from all other tunable lens units. In still other embodiments each cell comprises two or groups or subsets of tunable lens units wherein each the tunable lens units within a group or subset can only be controlled collectively whereas the tunable lens units of a first group or first subset can be controlled individually from the tunable lens units of other, second group(s) or subset(s) of the set of lens units.

For instance, figure 6A shows an embodiment wherein the optical device 1 only has one single lens cell 141. In this embodiments the single lens cell 141 may be embodied has having a ring-shaped, single closed space filled with a single volume of LC material. Various electrodes are provided at a plurality of different locations throughout the closed space of the lens cell to provide at those positions a plurality of different tunable lens units, for instance a number of lens units evenly distributed along the length of the ring-shaped closed space. Similarly, in the embodiment shown in figure 6B, the optical lens 3 comprises three lens cells 141, 142, 143, the three lens cells forming three concentric rings. Again, each of the lens cells 141, 142, 143 has a single closed space filled with LC material. In the closed space of each of the lens cells 141, 142, 143 transparent (for instance, patterned) electrodes are provided at a plurality of different locations throughout the closed space for forming a plurality of tunable lens units. Each of the tunable lens units in a lens cell shares the same closed space with LC material as the other tunable lens units of the lens cell.

In the following figures. several further embodiments of optical lenses are shown wherein both tunable lens units and static lens units are applied in combination. The tunable lens units may be combined with static ones in various different combinations serving various different functions, as will be elucidated hereafter.

In figures 7A-7D, a set of possible configurations of the two types of lens units is shown using schematic drawings (following the manner of representation of the lens units 14, 16, 18 of figures 4A, 4B, 4C, respectively). There are many ways in which tunable and static lens units may be combined in a single optical lens 1, the different configurations all having their own advantages.

For example, tunable lenses may be applied in the regions of the optical lens that typically remain uncut during preparation, to avoid waste of lens material (especially waste of tunable lens units).

Alternatively or additionally, tunable lens units may be arranged in regions of the lens where they are most useful. Furthermore, tunable lens units and static lens units may be combined to reduce costs or complexity.

Figure 7C shows an embodiment wherein the area with tunable lens units (and therefore the second refraction area) is confined to a predetermined outline or perimeter. Two possible outlines 18 and 19 are shown. Outline 18 is circular and is centered around the center area 12 of the optical lens. Outline 19 is oval shaped and has a more oval shape one skewed downwards, or, towards the side of the optical lens that will become the bottom side of the lens in use.

It can be advantageous to limit the area with tunable lens units when considering integration in frames with varying shapes. By limiting the application of tunable lenses to a certain area that is less likely to be cut away upon preparation of the optical lens 1, the number of tunable lenses wasted can be increased. Besides a centrally positioned outline, one could have a more oval one skewed towards the bottom, to account for typical frame shapes and pupil positions.

Note furthermore that the exact frame shape will typically not be known upfront, meaning the overall lens will need to be prepared in a standard size, usually a 65 mm round shape. Once the shape 1s known the outline of the frame and its position with respect to the optical center of the lens can be fixed. However, this means the shape could arbitrarily cut the lens units in any given area. As this might affect the operational working of the tunable lens units, a solution would thus be to limit the tunable lens units to an area that would typically not get cut and extend the areas beyond that with static lens units. A typical outline would be a circular area of tunable lens units concentrically positioned with respect to the optical center of the lens. Next to this, one could take into account that most frame shapes are rather oval, and the optical center tends to be fitted rather upwards in the frame shape. Hence, the outline of the tunable lens units could be oval shaped and more downwards with respect to the optical center of the lens.

Another approach is to mix the tunable lens units with static ones in patterns similar to the standard patterns. For instance, one could implement every second concentric ring as a tunable version. An example of this embodiment is shown in figure 7D.

It should be noted that the pitch does not need to be the same as the original static design and may be smaller as the power of the lens units can be reduced to zero. One could design this to achieve a target (or range of) visual acuity in different use cases. These rings can then be activated when additional peripheral blur seems warranted.

Alternatively. in each ring every other single lens unit could be a tunable one. Such an embodiment is shown schematically in figure 7B. The parameters of the optical lens, for example pitch size, refractive power of the lens units, number of rings, number of lens units, etc., could be adapted to target a certain visual acuity.

Obviously, many more combinations are possible. One could combine tunable and static lens units only in certain directions or quadrants (e.g. only having tunable lens units in the vertical or horizontal direction). Figure 7A shows a schematic drawing of an optical lens 1, comprising lens units. The optical lens is divided in four sections; upper, lower, left and right. The upper and lower section of the optical lens comprise only static lens units 16. In the left and right sections, all lens units are tunable 14. In this embodiment, the tunable lens units are only present in a more horizontal direction. This could be advantageous because this is the primary direction of eye movements.

Similar approaches can be considered in the other arrangements, for example in the earlier- mentioned honeycomb configuration. In the honeycomb configuration, dispersed, well-chosen tunable lens units can be considered, or ring-like design following the honeycomb outline.

In every embodiment, the optical power of a static lens unit 16 can be combined with a tunable lens unit 14 by arranging them on top of each other. For example, the static lens unit can be arranged at the outer surface of the optical lens and the tunable lens unit then is arranged below the static lens unit, embedded in the optical lens (see figure 5 discussed earlier).

Tunable lenses may be actively tuned in different ways and/or at different moments in time. One way to adjust the refractive power of the tunable lens units 14 in the optical lens 1 is to adjust the refractive power upon preparation of the optical lens. For example, after the personal parameters of the user have been determined and the personal preferences have been discussed, the refractive power of the tunable lens units can be adjusted and customized accordingly, before assembling the optical lens in the optical device, for example spectacles.

Additionally or alternatively, an optical lens comprising tunable lenses that are configured to be tuned on demand, i.e. when the optical lens is in use. For example, an electronic controller could be provided configured to control the refractive index of the tunable lens units. Figures 8A- 8C and 9A-9D show a variety of possible embodiments comprising tunable lens units electrically connected to a controller.

When all or a subsection of the lens units are tunable, one could adapt the power of the lens units according to the specific situation or surrounding conditions. For example, when a bright and/or outdoors environment is detected, the power could be reduced to improve the visual acuity for far vision gazing. Or, when a dark or indoor environment is detected, the power could be increased to enhance the treatment effect. Alternatively, when a reading or near activity is detected, the power could be increased to enhance the treatment.

Figures 8A, 8B, and 8C show possible embodiments comprising tunable lens units connected to a controller configured to control or manipulate the refractive index of the tunable lens units. Figure 8A schematically shows the features of a minimalistic embodiment according to the present disclosure. Two tunable lens units 14 are shown in the optical lens 1. Both tunable lens units are connected to a separate controller 20,22 (also referred to as controllers ci, ¢2) using connecting elements 21, like electrically conductive (metal) wires or (patterned) (metal) layers.

Each of the controllers (ci, cz} is configured to control the one or more tunable lens units it is connected to. In the shown embodiments, both lens units in the device can be controlled or tuned separately and independently of each other. In further embodiments multiple controllers (cy. ¢2) (and sensors) can be integrated into one controller (and sensing) unit or multiple controllers (ci, ¢2) may in turn be controlled by a further controller connected to both controllers (ct, ¢2). In further embodiments, a single controller is used for controlling the lens units of two or more optical lenses 1, for instance the optical lenses 1 of an optical device 100 like a pair of glasses. The controller may be integrated with at least one of the optical lenses 1 and/or may be accommodated in the frame of the optical device 100.

In these and all following figures, the controllers are shown schematically to indicate separate and independent control areas/sets of tunable lens units. It is clear that the combination of these individual controllers can be considered the constitute the controller of the optical lens.

The connecting elements 21 in the schematic drawings in the present disclosure function primarily as a schematical indication of the communicative connection between the lens units and the controllers. The tunable lens units are typically controlled using indium tin oxide (ITO) layers.

These layers are applied to at least the area of the tunable lens unit. The lens units may be connected to each other and the controller using some conducting material. The connecting elements 21 might thus comprise for example classical conductors like non-transparent wires, or transparent conductors like ITO layers. Furthermore, the lens units might be connected to each other using either of the previously mentioned or other conductive material.

Figure 8B shows an embodiment of the optical lens 1 schematically. In this embodiment, multiple rings of tunable lens units 14 are shown in the optical lens 1. The tunable lens units 14 of the inner cylindrical ring are connected to a controller 20, 22 by connecting elements 21. The embodiment is configured for separate controlling of the upper half of one ring and the lower half of that ring. Therefore, the tunable lens units 14 in the upper half of the inner ring are connected to a controller using first connecting elements 21 and the lower half is connected to a controller using second connecting elements 21. Hence, in this embodiment, the controller comprises at least two controllers.

As mentioned above, the controller in an embodiment of an optical device according to the present disclosure may comprise multiple controllers. For example, the controller may comprise a separate controller for all sets of tunable lens units that are controlled independently. By controlling the refractive power of one or more rings or sections thereof on demand, the visual acuity could be adjusted to match the personal or situational needs of the user. For example, higher visual acuity might be desired in an outdoor environment, or a busy room, whilst less visual acuity is required at home or in a dark environment.

These figures aim to show some different ways in which tunable lens units could be controlled and combined. The tunable lenses may be controlled and tuned based on for example personal parameters, personal preferences, the situation or activity of the user, or environmental conditions. Many alternative embodiments are possible. For example, the lower section of lens units could be tuned with a controller based on the activity of the reader, for example reading, using a sensor, for example a proximity sensor or gaze tracking sensor.

For tuning the refractive power of the lens units based on changing conditions or parameters, it may be convenient to tune the lens units based on the external electrical signal from one or more sensors. For example, the refractive power of the tunable lens units may be tuned automatically based on these sensor signals. In the preferred embodiments, the sensor is configured to determine/receive at least one of: an environmental condition, such as the brightness of ambient light. the proximity of an object to the lens element, for instance a book, a display (tablet, telephone), the orientation of the lens element relative to the force of gravity (reading orientation), current and/or past activity of the user; a direction of the gaze of the user, communication signal from another device, for example a phone or watch.

In figures 9A-9D, several further embodiments comprising tunable lens units connected to a controller are shown schematically, wherein the controller is configured to receive a sensor signal from one or more sensors.

In figure 9A, multiple rings of tunable lens units 14 are shown in the optical lens 1. The number of rings shown in this figure is two, but this number may vary of course. Static lens units may be incorporated as well. The rings are connected to the controllers 20,21 by connection elements 21. The controller is configured to control the rings of tunable lens units 14 independently. A sensor 30 is connected to the controller. The controllers may be configured to control the tunable lens units based on signals from the sensor automatically. In the embodiment shown in figure 9A, the optical lens can be adjusted to provide for example increased or decreased optical acuity, depending on the input from the sensor and varying along the radial distance from the optical center.

An embodiment like this, wherein the cylindrical or hexagonal rings are controlled independently, is suited to adjust for situational and environmental changes. For example, the optical lens 1 according to figure 9A could be configured to increase visual acuity when an outdoor environment and/or a high activity is measured, and to decrease visual acuity when an indoors environment and/or low activity is measured. The difference in refractive index between the inner and outer rings may also be adjusted accordingly. Furthermore, in this embodiment, the refractive power of the tunable lens units could be adjusted to the radial position of the gaze of the wearer.

In the embodiment of figure 9B, only one ring of lens units is shown schematically.

Tunable lens units 14 are connected to a controller comprising multiple controllers. This embodiment is configured to control all tunable lens units individually by using separate connection elements 21 and controllers. A sensor unit 30 is connected to the controller.

Figure 9C shows another possible embodiment schematically. Multiple rings of lens units are shown in the optical lens 1. The lens units are divided in four sections and corresponding sets.

The upper section and lower section comprise only static lens units 16. The sections in the horizontal direction comprise tunable lens units 14. The left section comprises a first set of tunable lens units and the right section comprises a second set of tunable lens units. Both sets are separately connected to a controller by connection elements 21. This embodiment is configured to control the left and right set of tunable lens units 14 separately and independently.

Since the primary direction of eye movements is horizontal, it could be efficient to control only these sections. However, different distributions and division of separately controllable sets of tunable lens units are also possible and some will be considered in the following figures.

Figure 9D shows a schematic of an alternative conceptually similar embodiment, the tunable lens units are divided in multiple sections, corresponding to different angular directions.

Every angular direction section comprises one set of tunable lens units 14. All sets are connected to a controller in the controller by connecting elements 21. This embodiment is configured to control the angular sets of lens units individually and independently.

The embodiments in figure 9B, 9C, and 9D, wherein the refractive power of different angular sections can be controlled individually, are especially suited for combination with a gaze sensor. Embodiments comprising angular division of sets of tunable lens units connected to the controller and a gaze sensor connected to the controller, enable the controller to tune the power of the lens units according to the gaze direction of the wearer. For example, when the gaze of the wearer is tracked, the refractive power of the area in the direct line-of-sight could be reduced or made zero. In this way, the visual acuity would always be perceived as high, while the peripheral blur would always be present.

Note that in embodiments configured for gaze direction dependent control, there could also be lens units present in the central area, which would typically not contain any lenslets. An embodiment comprising lens units in the central area is drawn schematically in figure 10B. These embodiments could also be combined with a proximity sensor, allowing the controllers to adjust the refractive power of the tunable lens units according to the direction of the gaze and the proximity of objects in that direction.

Figure 9E shows schematically an embodiment comprising multiple rings of tunable lens units that is configured to respond to a signal from an external device. In the figure, the optical lens 1 comprises two rings 117, 11° of tunable lens units 14. The rings are separately connected to controllers 20 and 22 by connecting elements 21. The controllers 20,22 are furthermore connected to a sensor 30. In this embodiment, the sensor 30 comprises of a sensor part that is at least configured to receive signals from an external device 31. The optical lens 1 is thus configured to control the tunable lens units 14 based on the signal from the external device 31, and to control the radial rings separately and independently.

An embodiment like the one shown schematically in figure 9E is suited for controlling the tunable lenses based on many factors. For example, the external device 31 could be an electrical device like a smartphone. The smartphone may send sensor signals wirelessly to the sensor 30 of the optical device 1. The received sensor signals then are sent to the controller. The controller determines if and how the tunable lens units of the optical lens are to be controlled and then generate one or more control signals that are sent to the respective lens units.

Figures 9A-9E represent all similar embodiments, including for example embodiments with a different number or division of sections, more or less lens units (per section), and embodiments with a different configuration of static and tunable lens units.

Figures 10A and 10B are schematic drawings of embodiments that additionally comprise tunable lens elements in the center area of the optical lens 1. Figure 10A shows an example of an embodiment comprising one tunable lens unit in the central area of the lens unit. Around the central area, the optical lens 1 comprises multiple cylindrical rings of lens units 10. These lens units 10 might be either tunable or static. Figure 10B shows an example of an embodiment comprising multiple tunable lens units in the central area of the lens unit. Around the central area, the optical lens 1 comprises multiple cylindrical rings of lens units 10 that might be either tunable or static. Figure 10A and 10B represent all similar embodiments comprising tunable lens units in the central area of the optical lens 1. Embodiments like these are suited for combination with gaze tracking sensors. Furthermore, these embodiments might be used to increase clinical effect of the optical lens. For example, the tunable lens units in the central area of the optical lens might be tuned based on the activity of the user. When low visual acuity is required or desired, the refractive power of the tunable lens units could be altered accordingly. An embodiment comprising tunable lens units in the central area might additionally function as a multifocal lens that adjusts according to the activity or needs of the user. Note that any increase or decrease f refractive power in tunable lens units could range between a high-power value and all the way down to no/zero residual power.

Figure 11A is a top view of a further embodiment wherein the refractive power of the tunable lens unit in the second refraction area 5 is caused to vary as function of the radial distance (R) of the lens unit relative to position in the central area 12, for instance — but not limited to — the center of the central area 12. Figure 11B is a graph showing an example of how the refractive power (P) may be varied as function of the radial distance (R) from the center of the optical lens.

More specifically, figure 11A shows an optical lens 1 comprising multiple rings 11 — 11* of lens units 10. The arrow indicates the direction of increasing radial distance from the center of the optical lens 1. In figure 11B, the refractive power profile of the lens units in the embodiment drawn in figure 11A is shown as a function of the radial distance R from the center of the optical lens 1. In this embodiment, the refractive power of the lens units increases in a stepwise manner as the radial distance of the lens unit to the center of the optical lens 1 increases. Other distributions of refractive power profiles across the optical lens are possible as well This feature could have beneficial effects, possibly increasing the clinical effect of the optical lens whilst preserving visual acuity in the optical center of the optical lens 1 for the user.

This effect could be accomplished using only tunable lens unit or using a combination of tunable lens units and static lens units. When using static lens units, the tunable lens unit make it possible to adjust the refractive power provided by the static lens units so that the refractive power can be easily adjusted to the users’ individual anatomical parameters, preferences, or conditions.

The use of tunable lens units could thus improve the treatment effect, by tuning the trade-off between target treatment and acceptable remaining visual acuity.

In figures 12A and 12B, two further types of power distributions of the lens units across the optical lens are drawn schematically. In figure 12A, an exemplary embodiment of adapting tunable lens units is shown schematically, according to one type of response distribution of the refractive power of the tunable lens units to applied voltages. On the y-axis, the refractive power of the tunable lens unit is shown. On the x-axis, the radial distance of the ring of lens units to the center of the optical lens is shown. The refractive power on the y- axis is the power on top of the background power of the lens. The refractive power of the tunable lens units in this exemplary embodiment can be tuned according to the applied voltage. When a first voltage V1 is applied, the refractive power of the lens units reaches a first value. When a second voltage V2, different from the first voltage V1, is applied, the refractive power of the lens units reaches a second value. And, when a third voltage V3, different from the first voltage V1 and the second voltage V2, is applied, the refractive power of the lens units reaches a second value. The refractive power of the tunable lens units is added to the background power, i.e. the refractive power of the first refractive area.

In this exemplary embodiment, the tunable lens units are configured to have an equal response to an equivalent applied voltage. Thus, the response function of the refractive power of the tunable lens units is equal for all tunable lens units. In embodiments like this, a gradient in the refractive power profile of the lens units can be accomplished by applying different voltages to for example different cylindrical or hexagonal rings of tunable lens units.

Typically, the range wherein the voltage of the tunable lens units are tuned is between OD and +5.5D. However, in alternative embodiments, tunable lens units can also reach negative refractive powers and/or higher refractive powers.

In an alternative exemplary embodiment of adapting tunable lens units, the response of the refractive power on an applied voltage varies per lens unit. In this alternative embodiment, the refractive power of the tunable lens units depends on the applied voltage according to a varying response function. For example, one ring of tunable lens units might respond differently to an applied voltage then its neighboring ring of tunable lens units. In an embodiment like this, the refractive power of the tunable lens units might be equal across the entire optical lens when no voltage is applied. When a voltage V1 is applied, it results in a power profile with a gradient across the radial distance R from the center of the optical lens 1, like shown schematically in figure 12B. In the embodiment represented by figure 12B, the refractive power of all tunable lens units is equal when no voltage is applied. As a response to an applied voltage V1, the refractive power of the tunable lens units in the two inner rings 11! and 11? decrease, the inner ring 11! more strongly than 11%, whilst the refractive power of the tunable lens units in the two outer rings, 11% and 11°, increases, the outer ring 11* more strongly than 11°. This results in a gradient in the refractive power distribution across R. In certain embodiments, a gradient in the refractive power profile of the lens units can be accomplished by applying one voltage to all cylindrical or hexagonal rings of tunable lens units.

Furthermore, in both types of refractive power response functions, the distribution range of the refractive power of a tunable lens unit as a response to applied voltages can be discrete or continuous.

Figures 13A-13C are additional exemplifying embodiments of an optical lens according to the present disclosure, wherein different arrangements and configurations of tunable and static lens units and sensors are combined. These figures aim to give an indication of the variety of possible embodiments that could be created with the possible variations discussed in the present disclosure.

In figure 13A, an exemplifying embodiment is shown schematically. An optical lens 1 is drawn comprising two cylindrical rings of lens units, defining the second refraction area of the optical lens. In the center 12 of the optical lens 1, there are no lens units. The center area 12 thus constitutes at least part of the first refractive area. The lens units are divided into four sections. The upper section comprises only static lens units 16.

The lower section comprises only tunable lens units 14, grouped together in one set, connected to a controller C2 using connection elements 21. In the right and left section. static lens units 16 are mixed with tunable lens units 14 in an exemplary distribution. The tunable lens units 14 of the right and left section are connected by connection elements to the same controller C1. The controllers are connected to a sensor unit S. This embodiment is configured to tune the tunable lens units of the right and left section together, and the lens units in the lower section separately and independently from the horizontal sections, based on signal from the sensor unit. The sensor unit may comprise multiple sensors. For example, the lens units in the horizontal sections may be tuned by the controller based on the environmental conditions sensed by the sensor unit. Furthermore, the lens units in the lower section may be tuned by the controller based on the activity of the user sensed by the sensor unit, or the proximity of objects sensed by the sensor unit.

In figures 13B and 13C, other exemplifying embodiments are shown schematically.

An optical lens 1 is drawn comprising four cylindrical rings of lens units, defining the second refraction area of the optical lens. In the center 12 of the optical lens 1, there are no lens units. The center area 12 thus constitutes at least part of the first refractive area. Static lens units 14 are combined with tunable lens units 14 and lens units 10. Different sections and sets of tunable lens units 14 can be controlled separately and independently by the controller and based on a signal from the sensor unit.

When considering liquid crystal (LC) based tunable lenses a variety of implementations are possible. In one embodiment, the tunable lens would constitute of a liquid crystal cell in which a diffractive structure or a (Fresnel) lens structure is present, onto which a cholesteric liquid crystal is residing. With a carefully tuned helical pitch the cholesteric liquid crystal will act as an isotropic material of which the refractive index can be changed in the visual part of the spectrum when applying an electrical field. Typically,

this is achieved by transparent electrical conductors residing on either side of the liquid crystal cell (one on the counter substrate and one above or below the lens structure).

In another embodiment there would be a conventional nematic liquid crystal present on top of the (Fresnel) lens, with its long axis aligned in a preferred linear direction. In figures 14A and 14B such an embodiment of a tunable lens unit is shown schematically. In this configuration, the tunable lens would only work for the incoming light having its polarization vector parallel to the alignment direction (the perpendicular orientation would have a static response). Such a property could be exploited as to only have a tunable lens unit operate for one polarization of the incoming light. Such a feature is useful when looking at digital screens, which generally emit polarized light. Next to this, when the incoming light is unpolarized, 50% of the light will experience a tunable response by the lens units, while the other 50% will experience a static response. When one e.g. matches the ordinary index of the liquid crystal with the index of the integrated (Fresnel) lens, the static response will be an unaffected response (i.e. as if there was no lens unit present). One could exploit this effect as to induce a dual response emanating from the same location on the lens {e.g. two focal lengths) while still containing a tunable component. This adds freedom to tailor the intended treatment to the specific situations or surrounding conditions, or to the wearer's anatomical parameters (e.g. axial length).

In figures 14A and 14B, a schematic of tunable liquid crystal lens embodiment is drawn. The liquid crystals have a preferential linear alignment direction, indicated by the arrow, along the x-direction. When applying an electrical field a variety of alignment states of the liquid crystal molecules can be generated. Two extreme cases are shown here in figures 14A and 14B respectively. In one state, figure 14A, the liquid crystals are aligned along the y-axis, in the other figure, i.e. in figure 14B, they are aligned along the x- direction. When the refractive index of the lens is e.g. matched with the LCs ordinary refractive index both incoming orthogonal polarizations are unaffected in State 1. In the second state only the polarization in the x-direction, parallel with the linear alignment direction, is affected to, for instance, converge to a focal point.

While manufacturing efficiency could require that all lens units have the same linear alignment direction, this is not obliged. The orientation of the linear alignment direction in principle can be randomly distributed across all lens units in a lens and can be adjusted according to the desired optical effect. For instance, when one does apply a uniform linear direction across all lens units, the response on an incoming polarized light beam will be the similar for all lens units. A configuration might exist where there is no optical response from the lens units (i.e. each lens unit had no power) for one linear polarization, while the orthogonal polarization does experience the power of all lens units, see figure 15. Such a feature is useful when looking at digital screens, which generally emit polarized light.

Figure 15 is a view showing schematically the polarization of incoming light in response to the presence of the tunable lens units in such an embodiment. When the tunable lens units have a uniform linear alignment direction 34, the optical response will generally be uniform. However, the optical response may be polarization dependent. For instance, in the arrangement shown in figure 15 wherein the linear alignment direction corresponds to the x-direction, incoming linear polarized light having its polarization direction parallel with the alignment direction (Ey) will experience a dynamic effect, while the orthogonal direction (E,) will remain static (e.g. no effect at all).

On the other hand, one could want to avoid such large polarization dependent optical response differences. The distribution of the orientation could for instance be tailored in such a way that, irrespective of the angle of the polarization vector of an incoming linearly polarized light beam, the optical response is always similar.

For instance, when considering cylindrical lens units, one could ensure the linear alignment direction is always oriented radially from the optical center (the concentric point of the cylindrical lens units). In this case, the ordinary axis of the liquid crystal is always oriented parallel with the local cylinder axis of the cylindrical lens unit (see figure 10).

Conversely, the extraordinary axis of the liquid crystal will reorient in the plane perpendicular to the local cylinder axis when an electrical field is applied. As a result, the power profile will vary between two extreme values across a 90-degree circumference angle, irrespective of the angle of the polarization vector of an incoming linearly polarized light beam. Only the orientation of the overall power profile will change. When considering centro-symmetric round lens units bearing a similar radially oriented alignment direction, a similar power profile across a 90-degree circumference angle will be present, with more or less discrete power jumps between the lens units. Similar to the cylindrical lens units, the power profile will vary between two extreme values across a 90- degree circumference angle, irrespective of the angle of the polarization vector of an incoming linearly polarized light beam.

Another benefit would be that one only needs one liquid crystal cell for each lens unit, reducing the manufacturing complexity. Alternatively, one can stack two liquid crystal cells with their linear alignment direction oriented in a 90 degrees angle, thereby always leading to a full polarization independent response.

Figure 106A is a top view of a such embodiment of an optical lens wherein the tunable lens units have their linear alignment direction 35 always radially from the optical center of the lens (i.e. the concentric point of the cylindrical tunable lens units). Figure 16B is a graph representing the optical power (D) of two different polarizations (Ex, Ey) as function of an angle (8). In the figure the linear alignment direction is always oriented radially from the optical center (the concentric point of the cylindrical lens units). The power profile will vary between two extreme values across a 90-degree circumference angle (8), irrespective of the angle of the polarization vector of an incoming linearly polarized light beam (e.g. Ex or Ey). In this embodiment only the orientation of the overall power profile changes.

Another liquid crystal lens implementation does not use a lens structure within the liquid crystal cell but creates a desired phase front by changing the liquid crystal pretilt angle, while still keeping a linear alignment direction see figure 17A-17C. The pretilt angle can set by the alignment layer typically present at the inner sides of the liquid crystal cell and/or controlled by an external electrical field. Such an electrical field can be employed by a patterned (transparent) conductive layer, potentially supplemented with transparent resistive layers.

In figures 18A-18C, another embodiment is shown wherein a tunable liquid crystal lens is made by changing the liquid crystal pretilt angle and thereby creating the desired phase front in the preferred linear alignment direction (x-axis). By applying a voltage, the liquid crystal can be reoriented and the phase front adapted (see figures 17A-17C). Hence the power of the lens can be tuned.

Similar embodiments/solutions as with the (Fresnel) lens approach in the previous sections can be implemented.

During the manufacturing of the liquid crystal (LC) based lens units, one can choose to either have one single LC cell across several or all lens units (as discussed earlier, for instance in connection with the figures 6A and 6B), or distribute multiple LC cells across an aggregation of, or all lens units. Figure 19A shows an embodiment with a single, ring-shaped optical cell 144 containing multiple rings 111-116 of tunable lens units

10 arranged inside a single, ring-shaped closed space 37 filled with one volume of LC material. The ring-shaped closed space 37 is delimited by an outer seal 38, an inner seal 37, a top layer/substrate and a bottom layer/substrate so that the LC material is properly kept withing the closed space 37. A benefit of a single LC cell is that it would be relatively easy to manufacture. Furthermore, as the seal of a typical LC cell tends to scatter, a single

LC sell would have a limited seal length primarily located at the outer edge of the lens, reducing the amount of line scatter.

Figure 19 B show another embodiment of an optical device 1 wherein each lens cell 145 has a single tunable lens unit 10. The lens cell 145 has a seal 40 surrounding the closed space that accommodates the LC material of the tunable lens unit. The benefit of multiple LC cells 145 is there would be no LC present in areas where it is not needed. As

LC tends to have more bulk haze than conventional optical materials, this would reduce the overall haze of the lens.

It 1s to be understood that this invention is not limited to particular aspects described, and, as such, may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

Claims

CONCLUSIONS

1. An optical lens, for example a spectacle lens, intended to be worn in front of the eye of a user, the optical lens comprising: - a first refractive region having a first refractive power adapted to focus an image on the retina of the eye of the user; - a second refractive region having a second refractive power different from the first refractive power, and adapted to focus the image at a position in front of or behind the retina of the eye of the user; wherein the refractive power of at least a part of the second refractive region of the optical lens is tunable.

2. An optical lens according to claim 1, wherein the second refractive region comprises a set of tunable lens units, each of the tunable lens units comprising a lens portion having a variable refractive power value that is tunable or tuned by an electronic control unit connected to the tunable lens unit, the optical lens preferably being arranged such that a first subset of the tunable lens units can be tuned independently of a second subset of the tunable lens units.

3. An optical lens according to any preceding claim, comprising a transparent lens element comprising at least one transparent substrate, lens units being provided in and/or on the substrate.

An optical lens according to any preceding claim, wherein the second refractive region comprises one or more tunable lens units defining a variable refractive power value and one or more static lens units defining a fixed refractive power value.

5. An optical lens according to any preceding claim, comprising one or more tunable lens units adapted to allow variation of their respective refractive power values by the electronic control unit when the optical lens is in use.

6. An optical lens according to any one of claims 2 to 5, wherein a tunable lens unit is electrically connected to the electronic control unit, the control unit being adapted to select one or more values of the second refractive power for the lens unit from a range of second refractive power values, the range of second refractive power values being defined by a relatively high first refractive power value and a relatively low second refractive power value.

7. An optical lens according to claim 6, wherein the control unit and the tunable lens units are arranged to select refractive power values of a tunable lens unit from at least two, preferably three or more different discrete refractive power values.

8. The optical lens of claim 6, wherein the control unit and the tunable lens units are configured to select refractive power values in a continuous range between the first and second refractive power values.

9. An optical lens according to claim 6, 7 or 8, wherein the electronic control unit is adapted to vary the refractive power value of one or more of the tunable lens units in the second refractive region while keeping the refractive power value of one or more other lens units in the second refractive region substantially constant.

10. An optical lens according to any one of claims 2 to 9, wherein: - a plurality of lens units are collectively tunable; - a plurality of lens units are individually tunable; or - a first subset of the plurality of lens units is collectively tunable, - a second subset of the plurality of lens units is collectively tunable, and - the lens units of the first subset are tunable independently of the lens units of the second subset.

11. An optical lens according to any preceding claim, adapted to tune the optical refractive power of the portion of the second refractive region based on an external electrical signal.

12. An optical lens according to claim 11, wherein the external electrical signal is a sensor signal received from one or more internal or external sensors, the sensor and/or the electronic control unit preferably being adapted to determine at least one of the following: - an environmental condition, such as the brightness of ambient light;

- the proximity to the optical lens of an object, e.g. a book, a display (tablet, phone); - the orientation of the lens element with respect to gravity (reading orientation); - current and/or previous activity of the user; and - direction of the user's gaze.

13. An optical lens according to claim 11 or 12, wherein the external electrical signal is a communication signal from another device, for example a digital display, telephone or watch.

14. An optical lens according to any preceding claim, wherein the electronic control unit is adapted to control the one or more tunable lens units to adjust their respective refractive powers according to at least one of: - a first control signal received by the electronic control unit and representative of the brightness and/or darkness of the user's environment; - a second control signal received by the electronic control unit and representative of the user's current activity, for example by increasing the refractive power value when reading or proximity activity is detected; - a third control signal received by the electronic control unit and representative of the lens unit direction of the user's gaze.

15. An optical lens according to any preceding claim, wherein the plurality of lens units are arranged in a honeycomb pattern or in a pattern of one or more concentric rings.

16. An optical lens according to any preceding claim, wherein tunable lens units are combined with static lens units at corresponding positions on or in the lens.

17. An optical lens according to any preceding claim, wherein the second refractive region has an annular region surrounding the central region of the optical lens.

An optical lens according to any preceding claim, wherein tunable lens units are used in a first region of the second refractive region of the optical lens, the first region being oval-shaped and shifted downwards relative to the optical center of the lens and/or wherein static lens units are used in a second region of the second refractive region of the optical lens.

19. An optical lens according to any preceding claim, comprising one or more 53 annular concentric regions in which a combination of tunable and static lens units are arranged.

20. Optical lens according to 19, wherein in one or more of the annular regions tunable lens units and static lens units are alternated.

21. An optical lens according to claim 19 or 20, comprising a first annular region with only tunable lens units and a second annular region with only static lens units.

22. Optical lens according to any one of the preceding claims, wherein tunable lens units are combined with static lens units only in certain directions or quadrants, preferably in predominantly horizontal directions.

23. An optical lens according to any preceding claim, wherein one or more static lens units are combined with one or more tunable lens units by placing them one behind the other.

24. An optical lens according to any preceding claim, wherein tunable lens units are typically embedded in the lens.

25. An optical lens according to any preceding claim, wherein a tunable lens unit is arranged to change its refractive power for light of a first polarization direction and to keep its refractive power unchanged for light of a second polarization direction perpendicular to the first polarization direction.

26. An optical lens according to any preceding claim, wherein a central region of the optical lens also comprises tunable lens units.

27. An optical lens according to any preceding claim comprising a tunable cell comprising a single lens unit or a plurality of lens units, the tunable cell unit comprising liquid crystal and/or electrowetting based implementations.

28. The optical lens of claim 27, wherein the tunable cell comprises: - a first transparent substrate; - a second transparent substrate; - a first transparent electrode disposed on the first transparent substrate; - a second transparent electrode disposed on the second transparent substrate; - a connection element between the first and second transparent substrates, the connection element being adapted to define a closed space between the first electrode on the first substrate and a second electrode on the second substrate, the closed space being filled with liquid crystal (LC) material; - one or more control unit lines connected to the electronic control unit and the first and second transparent electrodes; the electronic control unit being adapted to control the orientation of the LC material in the closed space by applying a control signal to the first and second transparent electrodes.

29. An optical lens as claimed in claim 28, comprising means for adjusting a desired profile of liquid crystal initial state tilt angles across the interior of the closed space.

30. An optical lens according to any one of claims 27 to 29, comprising an alignment layer facing the closed space, the alignment layer preferably being configured to create a desired profile of liquid crystal initial state tilt angles varying across the alignment layer.

31. An optical lens according to any one of claims 27 to 30, wherein at least one of the first transparent electrode layer and the second transparent electrode layer is configured to create a desired profile of liquid crystal initial state tilt angles varying across the associated transparent electrode layer, wherein the at least one of the first transparent electrode layer and the second transparent electrode layer is preferably a patterned conductive layer.

32. Optical lens according to any one of claims 27 to 31, comprising a lens-shaped structure, for example a part of a diffraction element or a part of a Fresnel structure,

applied between the first and second transparent substrate, preferably applied within the closed space.

33. An optical lens according to any one of claims 27 to 32, wherein the liquid crystal (LC) material is a nematic liquid crystal material having its long axis aligned in one preferred linear direction.

An optical lens according to any one of claims 27 to 33, wherein the liquid crystal (LC) material is a cholesteric liquid crystal material, the cholesteric liquid crystal material providing a helical pitch to function as an isotropic material whose refractive index can be changed in the visual part of the spectrum upon application of an electric field.

35. An optical lens according to any one of claims 27 to 34, comprising a first lens unit having a first alignment direction and a second lens unit having a second alignment direction, wherein perpendicularly the first lens unit is disposed on top of the second lens unit while the first alignment direction is aligned with the second alignment direction.

36. An optical lens according to any one of claims 2 to 35, wherein the power of the lens units increases as the radial distance of the lens unit from the optical center of the optical lens increases.

37. An optical lens according to any preceding claim, comprising one or more static lens units, wherein a static lens unit is a non-controlled tunable lens unit and/or wherein a static lens unit is a fixed lens unit, preferably a lens unit without a lens portion whose refractive power is variable.

38. An optical lens according to any one of claims 2 to 37, wherein the electronic control unit is arranged to vary the refractive power value of a lens unit over time.

39. An optical lens according to claim 38, arranged to change the refractive power value by at least 50% within a second.

40. Optical lens according to claim 38 or 39, wherein the variation frequency of the refractive power value is greater than 50 Hz, preferably greater than 100 Hz.

41. An optical lens according to any preceding claim, wherein the refractive power and power distribution of the tunable lens units are adjusted to the anatomical parameters, e.g. the axial length, of the user.

42. An assembly comprising: - one or more optical lenses according to any one of the preceding claims; - a control unit connected to the one or more optical lenses and adapted to control the refractive power value of the second refractive region.

43. The assembly of claim 42, wherein controlling the refractive power value of the second refractive region comprises tuning the refractive power value or values of one or more tunable lens units arranged in the second refractive region.

44. An assembly according to claim 43 or 43, comprising one or more sensors adapted to sense one or more environmental/external conditions and output a sensor signal representative of the sensed condition, the control unit adapted to control the refractive power value of the second refractive region of the lens element based on the sensor signal received from the sensor.