WO2025037175A1

WO2025037175A1 - Customization and vision analysis system for the production of multifocal lenses

Info

Publication number: WO2025037175A1
Application number: PCT/IB2024/057224
Authority: WO
Inventors: Alessandro Cacciatori; Emilio Mazzocco; Francesco Mazzocco
Original assignee: Opto Plus Srl
Current assignee: Opto Plus Srl
Priority date: 2023-08-17
Filing date: 2024-07-25
Publication date: 2025-02-20
Anticipated expiration: 2026-02-17
Also published as: IT202300017343A1

Abstract

Vision analysis system for the production of customized multifocal lenses (100), adapted to be used for the design of a multifocal lens (1) tailored to the needs and physical conformation of a wearer (10), characterized in that it comprises: at least an acquisition device (110) adapted to analyze the behavior of a wearer (10) during the viewing of videos and images, also analyzing the reactions of the eyes to the stimuli; at least a digital apparatus (200) adapted to allow programming the inputs to be provided through said acquisition device (110), and for processing the data obtained, and for leading the design of the multifocal lens (1).

Description

“Customization and vision analysis system for the production of multifocal lenses”

Description

Field of the invention

The invention refers to the field of optics. Even more specifically, the invention is adapted to provide a system for the design and customization of multifocal lenses based on the individual functioning of the end user's vision.

Prior art

Multifocal or progressive lenses correct various vision defects, such as myopia, astigmatism and/or hyperopia.

A progressive lens is characterized by three different vision zones: far zone, zone for intermediate vision and zone for near vision. Among the features differentiating the various progressive lenses, the width and cleanliness of the progressive zones are the most decisive. Width of the progressive zone is intended as the size of the surface of the lens intended for the progressive zone. A progressive zone is defined as "cleaner" the lower the aberration values (astigmatism in jargon) are, measured in Diopters (D) which characterize each point thereof. An aberration/astigmatism value greater than 0.13 Diopters (D) is a value perceptible to the human eye, therefore, any value detected which is below 0.13 D indicates good cleanliness of the zone.

In general, it is always better to opt for a customized multifocal lens which allows customizing the geometric aspects based on visual features, the fit of the glasses on the face, posture and personal habits. A standard lens is cheaper, but does not allow modifying these parameters since it is not made “to measure.”

There are numerous patents which have addressed proposing increasingly advanced solutions with respect to the production, design of multifocal lenses and their customization, with some examples below.

One example is the subject of patent application KR20210064624 A of JK.H. LEE. The invention refers to a control unit for multifocal lenses and vision testing device.

Various embodiments of the invention refer to a multifocal control unit applied to a visual inspection apparatus comprising a camera and a lens. According to various embodiments, a multifocal control unit applied to a visual inspection apparatus comprising a camera and a lens comprises: a housing positioned between the camera and the lens and rotatable about an axial direction of the visual inspection apparatus; and a multifocal lens arranged in at least a portion of the housing and dividing one focus zone of the camera into at least two or more.

Another example is the subject of patent application KR102147201B1 of H. HWANG. The invention refers to an apparatus for the automatic inspection of a multifocal lens using a depth camera and the related operating method. According to an embodiment of the invention, the method comprises the steps of: photographing the ocular fundus, gradually compensating the blur on the fundus of the eye onto which a multifocal intraocular lens is inserted; calculating the sharpness for each blur of an image of the ocular fundus captured by the control unit; and quantifying the sharpness for the blurring by the control unit.

In the present invention, a system is provided comprising a virtual reality device capable of analyzing a user's vision habits. Virtual reality and its various uses are well known in the state of the art; in fact, two examples are given below whose use is similar to that of the present invention.

The first example is the subject of patent application US2003158497A1 of S.L. GRAHAM et al. The invention refers to a method and apparatus for the objective electro-physiological evaluation of visual function.

The present invention concerns the electro-physiological assessment of visual function using a stereo head-mounted display (e.g., virtual reality glasses) to display a stimulus which is used to generate a retinal or cortical response. In particular, the invention concerns a method for the objective electro-physiological evaluation of the visual function of at least an eye of a patient, which method comprises presenting a visual stimulus to at least an eye of the patient, recording at least a resulting response, chosen from the group consisting of a retinal response and a cortical response, generated following the presentation of the stimulus; analyzing said response; and as a result of said analysis, forming a map of the visual function of the patient's eye.

The second example is the subject of patent application CN108398788A of Z. XUEBING. The invention describes an eye tracking device and virtual reality imaging equipment.

The eye tracking device includes an electromagnetic radiation source, a lens, a first reflective film, a second reflective film, and an imaging device. The electromagnetic radiation source is configured to emit electromagnetic radiation towards the eyes; the lens is provided with a first side surface facing the eyes and a second side surface opposite the first side surface; the first reflective film is located on the first side surface of the lens and is used to reflect electromagnetic radiation; the second reflective film is placed on the second side surface of the lens and used to reflect electromagnetic radiation; the imaging device is used to receive electromagnetic radiation from the eyes; the first reflective film and the second reflective film are positioned to guide the electromagnetic radiation from the eyes to the imaging device.

The inventions reported so far, by way of non-exhaustive example, are representative of the inventive-technological framework available to date.

The object of the present invention is to provide a definitive solution to the problem of ensuring a customization suited to the needs of a user of multifocal lenses. The concept underlying the invention is to be able to apply variations to the width of the far and near vision zones (in a totally independent manner of each other) to the same design diagram of a lens, maintaining a cleanliness of the progressive zones with astigmatism values equal to or less than 0.05 D. The present invention involves the use of a virtual reality viewer capable of analyzing not only the movements of the wearer's head, but also his/her reaction times, his habits and his field of vision, or the use of a screen with one or more video cameras integrated (or other similar sensors) capable of detecting the movement of the head of the user sitting in front of him/her. The data analyzed in this way allows the production of a multifocal lens suited to the needs of its user.

Description of the invention According to the present invention, a vision analysis system is created for the customization and production of multifocal lenses tailored to their wearer.

The vision analysis is carried out by means of the use of an acquisition device for the automatic detection of the wearer's head movements and reaction times, so as to automatically indicate the widths of each zone.

The acquisition device can be of two types:

- virtual reality viewer;

- screen with one or more motion detection cameras.

In both cases, virtual sequences or settings are projected, in which the wearer is invited to follow the movement of an element (for example a red dot) which moves along the scene on the screen or in the virtual reality of the viewer.

The system calculates the head rotation values for each scene. Each wearer will obtain different values depending on age, joint mobility and vision habits. The head rotation values allow obtaining "vision maps" which will be processed by a processing algorithm to generate a design diagram whose progressive zones have widths specifically adapted to the wearer's needs and habits.

"Vision map" is intended as a graphic representation (through closed lines, through color gradients and/or other) of the zones in which the wearer has moved his/her gaze to view the virtual sequences or settings. The vision map thus allows knowing which zones are most frequently affected by the wearer's gaze, and together with the data on the rotation of the head, allow the processing algorithm to carry out an accurate design of the lens.

The objective of the present invention is to ensure that the right balance is always found between the width of the progressive zones of the far and near zones and the astigmatisms/aberrations of the peripheral zones of the lens.

Given that, by construction, the design diagrams of the present system have progressive zones (far and near) with astigmatisms/aberrations of a value equal to or less than 0.05D (therefore irrelevant for vision purposes), the astigmatisms/aberrations relevant for the purposes of vision (therefore with values greater than 0.13D as previously described) are always moved towards the peripheral zones of the lens.

By varying the width of the progressive zones (far and near) there is always a variation in the maximum astigmatism/aberration value in the peripheral zones of the lens.

The greater the simultaneous opening (i.e., width) of the progressive zones (far and near), the greater the peripheral astigmatism values will be. It is therefore not consequential that a design diagram obtains the best results in terms of visual comfort by increasing the width of all the progressive zones. A design diagram of a progressive lens obtains the best results in terms of visual comfort when a "right compromise" is found between the opening of the progressive zones, the "cleanliness" thereof and good astigmatism values detected in the peripheral zones of the lens.

The system of the present invention, as seen, comprises a digital apparatus and an acquisition device which can be a virtual reality viewer or a screen with a sensor apparatus.

The virtual reality viewer is worn by the future lens wearer so as to analyze the vision habits and reactions to visual stimuli thereof.

The viewer comprises a display which can be single or divided into two parts to provide a greater sensation of depth and realism, a sensor apparatus (such as, but not limited to, an accelerometer) which detects the inclination, position, movement, speed and acceleration of the viewer and a transmission apparatus which communicates wirelessly with the digital device.

The digital apparatus allows managing the inputs and outputs to be exchanged with the acquisition device. The digital apparatus comprises algorithms for acquiring and processing the data coming from the acquisition device, a simulation unit through which to define the scenarios to be transmitted to the acquisition device, a map of the cylinders showing the progressive zones to be created for the multifocal lens and on which the processing algorithm inserts the data related to the wearer's physiognomy and vision habits. More specifically, the processing algorithm calculates and provides the numerical data of the width of the various progressive zones to a laboratory technician or directly into the laboratory management software to create multifocal lenses tailored to said wearer's needs and habits. The operation of the main interaction, aimed at the creation of customized multifocal lenses, between digital apparatus and acquisition device can be described as follows: The acquisition device shows videos adapted to make the user follow a given element (for example a red dot) with his/her gaze. The sensor apparatus detects the movements of said wearer within a generic space. When the algorithm detects that when the element (for example the red dot) moves in a particular vision zone (for example the lower zone of the lens, the near vision zone) the wearer tends not to move his head (but to only move his/her gaze), it will ensure that this zone is larger on a design diagram, and thus on the final lens. On the contrary, if the algorithm detects that the wearer tends to move his/her head (for example to tilt it downwards rather than just moving the eyes downwards), it provides a smaller zone (always taking the lower zone of the lens, that for near vision, as an example).

In order to obtain rapid information on the quality (referring to vision comfort) of the calculated design diagram, a quality indicator is used.

The quality indicator can be a colored signal with three colors:

Green;

Yellow;

- Red.

After calculating the design diagram for a progressive lens, the maximum astigmatism value in the peripheral zones of the lens is detected. If the maximum peripheral astigmatism value is equal to or less than 1.1 times the value of the required addition (the addition refers to presbyopia and describes the difference between the dioptric value of near vision and the dioptric value of far vision, the additional value is always positive and is added to the distance gradation to obtain the near one), the quality indicator will be green and the lens will ensure optimal comfort.

If the maximum peripheral astigmatism value is comprised between 1.1 and 1.4 times the value of the required addition, the quality indicator will be yellow and the lens will be said to have good comfort.

If the maximum peripheral astigmatism value is greater than or equal to 1.4 times the required addition value, the quality indicator will be red.

If colored red, the operating mode involves proceeding to reduce the width of the progressive zones so as to lower the peripheral astigmatism.

The digital apparatus evaluates the quality indicator which represents the degree of vision comfort and good performance in providing a visual support of the lens. A good quality indicator is therefore related to a lens which does not cause excessive disturbance in vision, thus does not cause migraines, and has a low overall astigmatism value.

Based on the results obtained through the quality indicator, it is in fact possible to determine whether the astigmatisms are too invasive and cause a change in the wearer's vision habits. In this case, the digital apparatus, indicating a low quality indicator of the lens, can recommend or even automatically carry out a different design, providing a different opening of the vision zones with a relative different maximum astigmatism/aberration value in the peripheral zones of the lens.

This type of process can be carried out iteratively by the processing algorithm, going to refine the design diagram related to the lenses of a specific wearer precisely on his/her needs and vision habits measured and processed by means of the acquisition device. However, when the simulation of astigmatisms does not lead to significant changes in the wearer's habits, or excessive disturbances in vision, the digital apparatus determines a good quality indicator (for example yellow or green) of the lens designed with the design diagram.

The digital apparatus further allows to show the effect of the astigmatism/aberration zones by means of the cylinder map shown in 2D or 3D and/or by means of vision simulations. If the cylinder map shows the real effect of the cylinders on the lens, the vision simulations aim to simulate, approaching reality as much as possible, the effect which the lens will have when looked through. This type of expedient allows viewing, in videos, the effect which the disturbance caused by the aberrations of astigmatisms has on the wearer.

The advantages offered by the present invention are evident in the light of the description presented thus far and will be even clearer thanks to the attached figures and the related detailed description. Description of the figures

The invention will be described hereinafter in at least a preferred embodiment by way of nonlimiting example with the aid of the appended figures, in which:

- FIGURE 1 shows a general view of the vision analysis system 100 for the production of customized multifocal lenses;

- FIGURE 2 shows a diagram with a design diagram 240 explaining the calculation of the width 6 of the vision zones 2;

- FIGURE 3 shows three design diagrams 240 with different widths 6 for vision zones 2.

Detailed description of the invention

The present invention will now be illustrated by way of a purely non-limiting or binding example, resorting to the figures which illustrate some embodiments with respect to the present inventive concept.

FIG. 1 shows a general view of said vision analysis system 100 for the production of multifocal lenses according to the present invention. In FIG. 1 as in the following description, the embodiment of the present invention currently considered the best is illustrated.

Said vision analysis system 100 is adapted to be used for the design of a multifocal lens 1 tailored to the needs and physical conformation of a wearer 10 and comprises at least an acquisition device 110 with a display 111, a sensor apparatus 114, a transmission apparatus 120, a digital apparatus 200 with a database 201, an acquisition algorithm 210, a processing algorithm 220, a simulation unit 230, a design diagram 240 with vision zones 2. Said acquisition device 110 is adapted to analyze the behavior of a wearer 10 while viewing videos and images, analyzing head movements and reactions to stimuli. Said digital apparatus 200 is instead adapted to allow programming the inputs to be provided through said acquisition device 110 and for processing the data obtained.

Said acquisition device 110 comprises said display 111 which shows videos and images to said wearer 10 and said sensor apparatus 114. In some embodiments of the present invention, said acquisition device 110 is a virtual reality viewer, the display 111 is therefore a single screen or divided into two parts of the viewer. When divided into two parts, the display 111 inside the viewer provides a separate vision for each eye of the wearer 10, ensuring a greater effect of realism and depth. In the embodiments in which said acquisition device 110 is a virtual reality viewer, said sensor apparatus 114 consists, by way of non-limiting or binding example, of one or more accelerometers, capable of detecting the inclination of the viewer with respect to the horizontal plane (parallel to the ground), its position in space, its movements, and its speed and acceleration of movement.

In other embodiments of the present invention, said acquisition device 110 is a monitor device which comprises said display 111 in front of which the wearer 10 can sit, and which comprises said sensor apparatus 114 which, by way of non-limiting or binding example, can consist of one or more video cameras adapted to capture the head movements of the wearer 10.

Said transmission apparatus 120 is lastly adapted to provide wireless communication with said digital apparatus 200.

Said acquisition algorithm 210 is adapted to acquire the data coming from said sensor apparatus 114, while said processing algorithm 220 is adapted to process them. Said simulation unit 230 is adapted to allow setting up virtual reality scenarios specifically designed to analyze in detail the visual response of said wearer 10. Said design diagram 240 is adapted to show the vision zones 2 to be created for said multifocal lens 1 and on which said processing algorithm 220 inserts the data related to the physiognomy and vision habits of said wearer 10, allowing a tailor-made creation of said multifocal lens 1. "Vision habits" is intended as the tendency of said wearer 10 to move the head more or just the pupils in the direction where he/she wants to look. The vision habits are analyzed, by way of non-limiting example, by noting how many times (out of the total visual stimuli received by means of said display 111) the wearer 10 moves or does not move his/her head to look in the direction of a stimulus provided by the movement of an element (for example a red dot) on the display 111 of the acquisition device 110. The processing algorithm 220 then calculates the numerical data of width 6 (shown in FIG. 2) of the vision zones 2 of said design diagram 240 to create said multifocal lens 1 which is tailored to the needs and habits of said wearer 10. Said processing algorithm 220 being able to carry out automatic iterations in the calculation of said width 6 to obtain maximum aberration/astigmatism values in said design diagram 240 which are preferably comprised between 1.1 and 1.4 times the value of the required addition (the addition refers to presbyopia and describes the difference between the dioptric value of far vision and the dioptric value of near vision, the additional value is always positive and is added to the far gradation to obtain the near one) and even more preferably less than or equal to 1.1 times the value of said required addition.

As seen, a multifocal (or progressive) lens 1 is characterized by three different vision zones 2: far vision zone 2', intermediate zone and near vision zone 2". Among the features differentiating the various multifocal lenses 1 , the width 6 is the most decisive for the far vision zone 2’ and the near vision zone 2”. The width 6 of the progressive zone or vision zone 2 is intended as the size of the lens surface intended for the vision zone 2. The width 6, evaluated according to the present invention is calculated by the processing algorithm 220 as schematically shown in FIG. 2. FIG. 2 shows how, around a design diagram 240 representative of the multifocal lens 1, said processing algorithm 220 constructs a theoretical square 3 whose geometric center coincides with the geometric center of the lens and whose side has a measurement equal to the diameter of the lens (i.e., the diameter of the design diagram 240) added to a fixed numerical value.

Theoretical curves 5 (preferably ellipses) having their center on two opposite sides of the square 3 are traced by said processing algorithm 220 to delimit the vision zones 2' and 2" (far vision zone 2' highlighted in the top part inside said design diagram 240, near vision zone 2” highlighted in the lower part inside said design diagram 240). A larger ellipse 5, i.e., having a larger diameter, determines a wider vision zone 2 and an ellipse 5 with a smaller diameter determines a less wide vision zone 2.

The width 6 of a progressive zone or vision zone 2 is calculated, according to the present invention, by measuring the distance between the two points of intersection between the extension of the curves 5 and the sides of the square 3. The present invention therefore provides a processing algorithm 220 capable of making variations in the width 6 of the vision zones 2 based on an analysis of the vision and habits of the wearer 10.

FIG. 3 shows three design diagrams 240 (FIG. 3 A, B and C) with different widths 6 for the vision zones 2' and 2". Specifically, the design diagram 240 shown in FIG. 3A has a width 6 of the vision zone 2' (at the top, for far vision) equal to 80mm and a width 6 of the vision zone 2" (below, for near vision) equal to 20mm. The black dot approximately near the center of the design diagram 240 of FIG. 3 A is positioned in the zone having the maximum astigmatism value and equal to 2.18 D. Since the value of the required addition (the addition carried out as known in the state of the art for the correction of a defect in vision) is equal to 2.00 D in the cases of FIG. 3 A, B and C, the maximum astigmatism is equal to 1.09 times the addition value and therefore a multifocal lens 1 produced with the design diagram 240 of FIG. 3 A will ensure an “optimal” comfort.

The design diagram 240 shown in FIG. 3B has a width 6 of the vision zone 2' (at the top, for far vision) equal to 95mm and a width 6 of the vision zone 2" (below, for near vision) equal to 35mm and the maximum astigmatism measured at the black point is equal to 2.63D. An astigmatism of 2.63 D is equal to 1.315 times the addition of 2.00D. A multifocal lens 1 produced with the design diagram 240 of FIG. 3B will ensure a "good" comfort and the processing algorithm 220 will be able, upon the request of a designer, to carry out further iterations to try to have a maximum astigmatism less than or equal to 1.1 times the addition of 2.00D or not to carry out any further changes.

The diagram shown in FIG. 3C has a width 6 of the vision zone 2' (at the top, for far vision) equal to 100mm and a width 6 of the vision zone 2" (below, for near vision) equal to 40mm and the maximum astigmatism measured at the black point is equal to 2.88D. An astigmatism of 2.88 D is equal to 1.44 times the addition of 2.00D. A multifocal lens 1 produced with the design diagram 240 of FIG. 3C will ensure a "low" comfort and the processing algorithm 220 will be able, upon the request of a designer, to carry out further iterations to try to have a maximum astigmatism between 1.1 and 1.4 or, preferably less than or equal to 1.1 times the addition of 2.00D.

FIG. 3 also shows, next to each design diagram 240, a quality indicator 4 adapted to provide, on a graduated scale, an indication of the expected quality, referring to vision comfort, of the multifocal lens 1 possibly made with such a design diagram 240. Finally, it is clear that modifications, additions or variations that are obvious to a person skilled in the art can be made to the invention described so far, without thereby departing from the scope of protection provided by the attached claims.

Claims

1. Vision analysis system for the production of customized multifocal lenses (100), capable of being used for the design of a multifocal lens (1) tailored to the needs and physical conformation of a wearer (10), characterized in that it comprises:

- at least an acquisition device (110) suitable for analyzing the behavior of said wearer (10) during the viewing of images and visual stimuli;

- at least a digital apparatus (200) suitable for allowing the programming of the inputs to be provided through said acquisition device (110) and for processing the data obtained; said acquisition device (110) comprises:

- at least a display (111) capable of showing videos and/or images with visual stimuli;

- a sensor apparatus (114) designed to detect the movement of the head of said wearer (io);

- a transmission apparatus (120) capable of providing wireless communication with said digital apparatus (200); said digital apparatus (200) comprising:

- an acquisition algorithm (210) suitable for acquiring the data coming from said sensor apparatus (114);

- a processing algorithm (220) suitable for processing the data acquired by said acquisition device (110);

- a simulation unit (230) designed to allow setting up virtual reality scenarios specifically designed to analyze in detail the visual response of said wearer (10);

- a design diagram (240) suitable for showing the vision zones (2) to be created for said multifocal lens (1); said design diagram being modified by said processing algorithm (220) on the basis of the data relating to the physiognomy and vision habits of said wearer (10), allowing a tailor-made creation of said multifocal lens (1).

2. Vision analysis system for the production of customized multifocal lenses (100), according to the previous claim 1, characterized in that said processing algorithm (220) is suitable for calculating the width (6) of the vision zones (2) of said design diagram (240) to create said multifocal lens (1) which is tailored to the needs and habits of said wearer (10); said processing algorithm (220) capable of carrying out automatic iterative calculations of said width (6) to reduce astigmatism/aberration values in said design diagram (240).

3. Vision analysis system for the production of customized multifocal lenses (100), according to the previous claim 1 or 2, characterized in that said acquisition device (110) is a virtual reality viewer that is worn by said wearer (10); said sensor apparatus (114) capable of detecting the inclination on the horizon of said virtual reality viewer, its position in space, its movements, and its speed and acceleration of movement.

4. Vision analysis system for the production of customized multifocal lenses (100), according to any of the previous claims, characterized in that said display (111) is a single display or divided into two parts providing a separate vision for each eye of said wearer (10) for a greater effect of realism and depth.

5. Vision analysis system for the production of customized multifocal lenses (100), according to the previous claim 1 or 2, characterized in that said acquisition device (110) is a display (111) arranged in front of said wearer (10), and that said sensor apparatus (114) includes one or more video cameras designed to monitor the movements of the head of the wearer (10) sitting in front of the display (111).