WO2025133288A1

WO2025133288A1 - Method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject

Info

Publication number: WO2025133288A1
Application number: PCT/EP2024/088157
Authority: WO
Inventors: Guillaume Giraudet; David Rio; Matthieu Guillot
Original assignee: Essilor International Compagnie Generale dOptique SA
Current assignee: EssilorLuxottica SA
Priority date: 2023-12-21
Filing date: 2024-12-20
Publication date: 2025-06-26
Anticipated expiration: 2026-06-21

Abstract

Method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject, said method comprising at least one iteration of the following steps: a) providing a pair of eyeglasses intended to be worn by the subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, b) after a period of time, collecting data relating to the visual behavior and/or the environment of the subject and determining a value of a myopia progression indicator for at least one eye of the subject. c) defining the optical lens design of the pair of eyeglasses based on the collected data and the value of the myopia progression indicator.

Description

« Method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject »

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject. It also relates to a pair of eyeglasses.

BACKGROUND INFORMATION AND PRIOR ART

Myopia of an eye is characterized by the fact that the eye focuses light coming from far distance of the eye in front of the retina. In other words, a myopic eye presents a length that is too important for clear far vision. Myopia has both genetic and environmental origins. In the latter case, it develops due to the increase in near vision tasks and to less outdoor activities.

Many solutions exist that aim at alleviating the discomfort induced by myopia and controlling myopia evolution. It is known in particular to use an ophthalmic lens intended to be worn in front of an eye of a wearer and having an optic zone comprising an arrangement of micro-optical elements having optical features adapted to alleviate the discomfort induced by myopia and to provide myopia control function in order to manage myopia progression. These solutions may be functional, but they do not consider the visual environment and the visual behavior of the subject that will wear this spectacle lens. Consequently, the design of those lenses determined by this latter method is not adapted to the visual environment and the visual behavior of the subject. The non-consideration of the visual environment and the visual behavior of the subject to determine a pair of eyeglasses could therefore alter the visual acuity of the wearer wearing those lenses.

SUMMARY OF THE INVENTION

Therefore, one object of the invention is to provide a method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject to determine a pair of eyeglasses with a better tradeoff for the subject between visual acuity and visual discomfort due to control of the optical features realizing the myopia evolution control.

The above object is achieved according to the invention by providing a method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject, said method comprising at least one iteration of the following steps: a) providing a pair of eyeglasses intended to be worn by the subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, b) after a period of time, collecting data relating to the visual behavior and/or the environment of the subject and determining a value of a myopia progression indicator for at least one eye of the subject c) defining the optical lens design of the pair of eyeglasses based on the collected data and the value of the myopia progression indicator.

Thanks to the collected data, it is determined the visual environment and/or the visual behavior of the subject and how this visual environment and/or the visual behavior of the subject evolves with time. Therefore, the pair of eyeglasses that can be provided after the step of controlling is thus well adapted to the visual environment and the visual behavior of the subject.

In addition, combining the collected data and the determined value of the myopia progression indicator makes it possible to consider the myopia evolution and/or visual discomfort due to the optical features realizing the myopia evolution control.

Consequently, the pair of eyeglasses can be customized for the subject based on his visual environment, on his visual behavior and his evolution of his visual performance and/or myopia discomfort over the time.

Therefore, the method can be used to provide a pair of eyeglasses having an optical lens design determined by considering the variation on his visual environment, on his visual behavior and his evolution of his visual performance over the time.

This makes it possible to determine a pair of eyeglasses with a better tradeoff for the subject between visual acuity and visual discomfort.

In one embodiment, the pair of eyeglasses provided at step a) comprises a optical lens design, said optical lens design (of step a)) comprising an optical lens design of the first lens of the pair of eyeglasses and an optical lens design of the second lens of the pair of eyeglasses, the optical lens design of the pair of eyeglasses defined at step c) being also based on the optical lens design of the pair of eyeglasses provided at step a).

In one embodiment, the optical lens design of the pair of eyeglasses determined at step c) comprises an optical lens design of the first lens of the pair of eyeglasses and an optical lens design of the second lens of the pair of eyeglasses, the optical lens design of the first lens of the pair of eyeglasses and the optical lens design of the second lens determined at step c) being each based on the collected data and the value of the myopia progression indicator and, optionally, on the optical lens design of the given lens provided at step a).

Other advantageous characteristics of the method of this invention, taken together or separately, are given in claims 2 to 14.

In one embodiment, the arrangement of micro-optical elements of each lens of the pair of eyeglasses comprises at least one feature, the step of defining comprising: - comparing the value of the myopia progression indicator to a threshold value,

- depending on the comparison, changing the at least one feature of at least a part of the micro-optical elements comprised in the arrangement of the micro-optical elements of at least one of the lenses of the pair of eyeglasses or keeping the at least one feature of the arrangement of micro-optical element of at least one of the lenses of the pair of eyeglasses.

In one embodiment, the step of changing (or keeping) is also based on the given collected data.

In one embodiment, in the step of collecting, measurements relating to the visual behavior and/or the environment of the subject are collected by means of at least one sensor device positioned on the frame of the pair of eyeglasses.

In this embodiment, the at least one sensor device may comprise two cameras positioned on two opposite sides of a fitting surface of a frame of the pair of eyeglasses oriented towards the field of view of the subject, each camera being associated to one of the lens of the given pair of eyeglasses and being arranged to provide at least one depth map of the environment positioned in the visual field of view of the subject, said at least one depth map being comprised in the collected data.

Alternatively, in this embodiment, the at least one sensor device comprises two cameras positioned on two opposite sides of a fitting surface of a frame of the pair of eyeglasses oriented towards the field of view of the subject, each camera being associated to one of the lens of the given pair of eyeglasses, said at least one sensor device being arranged to provide at least one depth map of the environment positioned in the visual field of view of the subject from two images acquired simultaneously by the two cameras, said at least one depth map being comprised in the collected data.

In this embodiment, the at least one sensor may be arranged to provide at least six depth maps per hour. In this embodiment, depth maps may be provided by the at least one sensor device. Each depth map may be associated with time data.

In this embodiment, in the step of collecting, depth maps may be provided (and optionally with time data, said time data comprising a time of acquisition of the two images), after the step collecting, the method may comprise a step of analyzing the collected data by a computer, said step of analyzing providing at least one of the following elements:

- a value of proximity over time, said value of proximity corresponding to the inverse of an average depth computed from the depth maps (and optionally from time data);

- a parameter of symmetry between the two lenses of the pair of eyeglasses, said parameter of symmetry being computed from the depth maps associated to the first eye and the second eye, said at least one element being used in the step of defining c). In one embodiment, the parameter of symmetry may be based on the value of proximity over time.

Another object of the invention is to provide a pair of eyeglasses intended to be worn by a subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, said pair of eyeglasses having an optical lens design determined with the method according to the present disclosure, said pair of eyeglasses comprising a frame, and at least one sensor device positioned on the frame of the pair of eyeglasses and arranged to collect measurements relating to the visual behavior and/or the environment of the subject, said sensor device comprising a control unit to perform steps b) and c) of the method according to the invention (as disclosed above).

In one embodiment, the first lens comprises an optical lens design, the second lens comprises an optical lens design, said optical lens designs of the first lens and the second lens being determined by the method according to the present disclosure.

In this embodiment, the at least one sensor device may comprise two cameras positioned on two opposite sides of a fitting surface of a frame of the pair of eyeglasses oriented towards the field of view of the subject, each camera being associated to one of the lenses of the given pair of eyeglasses, said at least one sensor device being arranged to provide at least one depth map of the environment positioned in the visual field of view of the subject from two images acquired by the two cameras.

In one embodiment, each camera may be arranged to provide at least six depth maps per hour.

In one embodiment, the pair of eyeglasses may comprise a tracker device positioned on the frame and arranged to collect measurements relative to a gaze direction to determine a visual field of view of the first eye and a visual field of view of the second eye.

In an embodiment, each measurement relative to the gaze direction is associated to a depth map.

In one embodiment, the pair of eyeglasses is a smart pair of eyeglasses.

DETAILED DESCRIPTION OF EXAMPLE(S)

The following description with reference to the accompanying drawings will make it clear what the invention consists of and how it can be achieved. The invention is not limited to the embodiment/s illustrated in the drawings. Accordingly, it should be understood that where features mentioned in the claims are followed by reference signs, such signs are included solely for the purpose of enhancing the intelligibility of the claims and are in no way limiting on the scope of the claims.

In the accompanying drawings:

- Figure 1 shows a schematic perspective view of a pair of eyeglasses comprising a first lens and a second lens according to the present disclosure;

- Figure 2 shows a schematic axial cut view of a lens comprised in the pair of eyeglasses according to the present disclosure;

- Figure 3 shows a front view of an example of a lens comprised in the pair of eyeglasses according to the present disclosure, when projected into a facial plane perpendicular to the main axis of the lens;

- Figure 4 shows a front view of another example of a lens comprised in the pair of eyeglasses according to the present disclosure, when projected into a facial plane perpendicular to the main axis of the lens;

- Figure 5 shows an example of a method according to the present disclosure;

- Figure 6 shows an example of a human-machine interface used in a first step of collecting comprised in the method according to figure 5;

- Figure 7 shows an example of two images acquired simultaneously by cameras comprised in the frame of the pair of eyeglasses according to the present disclosure and an example of depth map obtained from these two images;

- Figure 8 shows an example of three distributions of proximity determined in the method according to the present disclosure;

- Figure 9 shows a table illustrating values of proximity determined by the method according to the present disclosure and obtained from the data of the three distributions of proximity shown in figure 8

- Figure 10 shows another example of a depth map determined by the method according to the present disclosure;

- Figure 11 shows an evolution of determined prolateness indicators as a function of time;

- Figure 12 shows an example of a first table used in a step determining the optical lens design of the pair of eyeglasses comprised in a method according to the present disclosure;

- Figure 13 shows an example of a second table used in a step determining the optical lens design of the pair of eyeglasses comprised in a method according to the present disclosure. Process

Figure 5 shows a first example of a method 100 according to the present disclosure.

The method 100 is a method for defining an optical lens design of a pair of eyeglasses 1000.

Optical lens design of the pair of eyec/lasses

It will be first disclosed with reference to figures 1 and 2, features of the pair of eyeglasses (or eyewear) 1000 obtained with the method 100 according to the present disclosure.

This pair of eyeglasses 1000 is intended to be worn by a subject.

This pair of eyeglasses comprises a first lens (corresponding to a spectacle lens) that is intended to be worn in front the first eye of the subject (for example in front the left eye of the subject) and a second lens (corresponding to a spectacle lens) that is intended to be worn in front the second eye (for example the right eye) of the subject.

As shown on figure 1 , two similar spectacle lenses 10, namely a right spectacle lens 10R and a left spectacle lens 10L are intended to be mounted on a frame 20 of spectacles in order to be positioned in front of the right eye E_R and the left eye E_L of the subject.

Figure 2 shows an example of one of the lenses, denoted spectacle lens, of the pair of eyeglasses.

The spectacle lens 10 is here a concave lens comprising a convex front face 11 and a concave rear face 12, but could alternatively be a concavo-convex lens or a planoconvex lens.

The spectacle lens 10 illustrated by figure 2 has two opposite optical faces, the front face 11 directed towards an object side and the rear face 12 that is closest to the eye ER, EL of the wearer. The spectacle lens 10 presents a center V10, which is typically the optical or geometrical center of the spectacle lens 10.

The spectacle lens defined according to the present disclosure is adapted to correct the vision of an individual (i.e. a wearer) in wearing conditions. The wearing conditions are to be understood as the position of the spectacle lens 10 in a spectacle frame 20 worn by the subject (also denoted wearer) in front of its eyes. The wearing conditions are defined according to physiological parameters of the wearer or to geometrical parameters of the frame 20 when the frame 20 is worn by the wearer. The wearing conditions comprise a pantoscopic angle, a cornea to lens distance, a pupil to cornea distance, an eye rotation center (ERC) to pupil distance and a wrap angle.

An example of standard wearing conditions may be defined by a pantoscopic angle of -8° for an adult or between 0° and 5° for a child, a cornea to lens distance of 12 mm, a pupil to cornea distance of 2 mm, an ERC to pupil distance of 11.5 mm and a wrap angle of 0°.

The pantoscopic angle is the angle in a vertical plane between the normal to the rear surface 12 of the spectacle lens 10 and the visual axis of the eye (axis A) in a primary position, defined as a horizontal direction, when the wearer gazes straight ahead at infinity.

The cornea to lens distance is the distance along the visual axis of the eye E in a primary position between the cornea and the rear surface 12 of the spectacle lens 10.

The wrap angle of the spectacle frame 20 is the angle in the horizontal plane between the normal to the rear face 12 of the lens at its center and the sagittal plane.

In the present disclosure, each spectacle lens 10 has an optical lens design comprising a macro-optical component and a micro-optical component.

The macro-optical component of the optical lens design of the given lens (also referred to as “macro-optical design” or “refraction area”) provides a macro-optical function providing at least one global refractive power over most or all the useful surface of the spectacle lens 10, to provide the wearer’s eye a dioptric correction adapted to the dioptric correction need of the subject in wearing conditions. For example, this macro-optical function is provided by the geometry of the front face 11 or of the rear face 12 or of both faces, typically by adapting the curvature radii of one or both faces of the spectacle lens. The refractive power of the spectacle lens 10 is generally comprised between ±15 diopters.

The refractive power provided by the macro-optical design comprises at least a spherical power and may also comprise a cylindrical power, a prismatic deviation power, according to the wearer’s correction need determined by an eye care professional in order to correct the vision defects of the wearer. Typically, the global refractive power corresponds to the dioptric correction based on a prescription of the wearer, for example in standard wearing conditions. For example, the prescription for an ametropic wearer comprises the values of optical power and of astigmatism comprising a cylinder and an axis for distance vision and/or for near vision.

The micro-optical component of the optical design (also referred to as “micro- optical design") of the spectacle lens 10 is made of several micro-optical elements 13 arranged on at least one of the front and rear faces of the lens, preferably the convex front face.

In the example illustrated on figure 2, the micro-optical elements 13 are located on the front face 11 of the spectacle lens 10.

Alternatively, at least a part or all the micro-optical elements 13 are located on the rear face 12 of the spectacle lens 10.

Still alternatively, at least a part or all the micro-optical elements 13 are located between the front face 11 and the rear face 12 of the spectacle lens 10. Still alternatively, at least a part or all the micro-optical elements 13 are formed on a film, in a form of a patch deposited on at least one of the front face 11 and the rear face 12 of the spectacle lens 10.

In a variant, at least part or all the micro-optical elements 13 are formed by lamination on at least one of the front face 11 and the rear face 12 of the spectacle lens 10.

In practice, the micro-optical elements are formed as a single integral part with the rest of the spectacle lens (typically by injection molding, press-molding, rolling or machining) or, as an alternative, on a film (forming of a patch or laminated) applied over one or both of the front face 11 and the rear face 12 of the spectacle lens 10.

This arrangement of all the micro-optical elements provides a micro-optical function which is distinct from and complements the macro-optical function. Thus, the global optical function of the spectacle lens 10 is the addition of its macro-optical function and of its micro-optical function respectively provided by the macro-optical and micro-optical components of its optical design. The micro-optical function of the spectacle lens 10 is the optical function provided by the spectacle lens 10 without its macro-optical design, that is without any global refractive power over most or all the useful radial width of the spectacle lens 10. The macro-optical function of the spectacle lens 10 is the optical function provided by the spectacle lens 10 without its micro-optical design, that is without any micro-optical element.

The arrangement of micro-optical elements of each lens comprises at least one of the following features:

- density of the micro-optical elements;

- dioptric power of the micro-optical elements;

- geometry of the micro-optical elements;

- refractive, diffractive or diffusive optical function of the micro-optical elements;

- size of the micro-optical elements;

- position of the arrangement of the micro-optical elements in a visual field of the first optical lens and of the second optical lens;

- position of the micro-optical elements in the arrangement of the micro-optical elements.

The density of micro-optical elements on a lens can be defined as the ratio between the total surface of the micro-optical elements and the area of the zone comprising the micro-optical element. Preferably, the density is selected such that the micro-optical elements 13 cover 20 to 95 percent (preferably 30-90 percent) of a first peripheral zone of the given lens.

For instance, each micro-optical element has its own optical function and has small dimensions of less than 2 mm, preferably less than 1 mm or preferably comprised between 0,3 millimeter to 2 millimeters. Each micro-optical element consists for example in a microlens, a Pi-Fresnel lens, a prism, a diffuser, a beam-splitter or a diffraction grating. The micro-optical elements are typically formed by photolithography, holography, molding, machining or encapsulation. Examples of the determination of the diameter can be found in the European application reference EP3923061A1 , in the PCT application reference WO2021/198362, in the PCT application reference WO2019/206569A1 and the PCT application reference WO2019166653A1.

Each micro-optical element provides a refractive, diffractive or diffusive function.

In an embodiment, a part or all of the micro-optical elements are refractive micro- optical elements. Each refractive micro-optical element can comprise a monofocal or a bifocal spherical dioptric power. Each refractive micro-optical elements, for example can have a spherical, aspherical or bifocal optical function.

In another embodiment, each or a part or all of the micro-optical elements are diffractive. Each diffractive micro-optical element comprises for example a diffractive Pi- Fresnel micro-lens, for example as disclosed WO2019206569. A diffractive Pi-Fresnel micro-lens has a phase function, which presents IT phase jumps at the nominal wavelength A0. The wavelength X0 is preferably 550 nm for human eye vision applications. The diffractive Pi-Fresnel micro-lens presents an optical axis passing through the optical center of the micro-lens. The micro-lens with diffractive Pi-Fresnel micro-optical elements mainly diffracts in two diffraction orders associated with two dioptric powers PO(AO) and P1 (A0). Thus, when receiving collimated light, the micro-lens concentrate light on two distinct areas on their axis.

For example, the dioptric power PO(AO) is comprised in a range of +/-0.12 diopter in addition to a sp hero-tori cal power of the predetermined refractive power of the spectacle lens, deriving for example from a prescription for the wearer.

According to an embodiment, the dioptric power P1(A0) is comprised in absolute value between 1 diopter and 10 diopters. Preferably, the dioptric power P1(A0) is comprised between ±2 diopters and ±6 diopters.

As an alternative, all or a part of the micro-optical element are diffusive micro- optical elements. Each diffusive micro-optical element comprises a diffusive micro-optical element scattering light. For example, a collimated light is scattered in a cone with an apex angle ranging from +/-1 ° to +/- 40°. In an example, the diffusive micro-optical elements are adapted to scatter light locally, i.e. at the intersection between the given micro-optical element and the wavefront arriving on the given micro-optical element. The micro-optical elements having a diffusive optical function may be similar to the micro-optical elements described in the document US10302962. The diffusive or scattering micro-optical elements are also for example as disclosed in WO2022074243. In an embodiment, each spectacle lens 10 is arranged for controlling the myopia growth.

In a non-limitative example, the arrangement of the micro-optical elements 13 of one of the spectacle lenses 10 has optical features to provide an evolution control function of the myopia for the eye of the wearer. In other words, the micro-optical elements 13 of the given spectacle lens 10 have each optical features adapted to control the myopia growth.

According to an embodiment, the arrangement of the micro-optical elements of the given spectacle lens is adapted to provide a specific spatial distribution of blur also called defocus effect. For example, the micro-optical elements comprise micro-lenses providing a refractive power that differs from the refractive power of the macro-optical component the optical design of the spectacle lens 10.

The myopia control signal depends on the features of the micro-optical elements, here based on the given evolution control function of the myopia. Typically, the myopia control signal depends on the refractive, diffractive or diffusive optical function of the micro- optical elements. To this end, the myopia control signal is:

- a diffusive signal if the micro-optical elements have a diffusive function. As explained above, the diffusive signal corresponds to a non-focused signal, typically a scattered signal;

- a diffractive signal if the micro-optical elements have a diffusive function. As explained above, the diffractive signal corresponds to a non-focused signal, typically a scattered signal;

- a refracted signal if the micro-optical elements have a diffusive function (defocus effect).

In the present disclosure, the arrangement of the micro-optical elements of a given lens can be the same over the surface of the spectacle lens 10.

In another embodiment, this arrangement of micro-optical elements can vary along the surface of the spectacle lens.

For example, figure 3 shows an example of an arrangement of the micro-optical elements over the surface of the given lens 10.

In this example, the given lens (for example the first lens) 10 comprises a central zone 14 bounded by a circular outline. In this example, the central zone 14 of the first lens 10 is without any micro-optical element and has a circular shape, for example of 4 millimeters in radius (defined in this example between the ophthalmic lens center V10 of the first lens 10 and the circular outline of the central zone 14).

The central zone 14 without any optical element is configured to maximize the acuity of the wearer in this zone as this zone does not comprise micro-optical element.

Of course, in other embodiments, the central zone 14 of the first lens 10 may have different shapes, for example hexagonal shape, or elliptical shape, or octagonal shape, or triangular shape, or polygonal shape, or asymmetrical shape, and different sizes, for example a transverse size or a diameter comprised between 2 and 6 millimeters.

The first lens 10 further comprises a first peripheral zone 15 arranged around the central zone 14 of the first lens 10. The first peripheral zone 15 is bounded internally by an inner outline which coincides with the outer outline of the central zone 14. In this example, the arrangement 11 of the micro-optical elements of the first lens 10 is disposed on the first peripheral zone 15 of the first lens 10.

The first lens 10 further comprises a second peripheral zone 18 arranged around the first peripheral zone 15. This second peripheral zone 18 is free of micro-optical elements and is used to adjust the given lens into the frame 20.

The central zone 14, the first peripheral zone 15 and the second peripheral zone 18 are concentric.

As shown on this figure 3, the first peripheral zone 15 is divided into two different intermediary zones, denoted first intermediary zone 15a and second intermediary zone 15b. Each of these zones can comprise an arrangement of micro-optical elements. In means that the arrangement of the micro-optical elements of the first intermediary zone 15a may differs from the arrangement of the micro-optical elements of the second intermediary zones 15b.

Of course, although is not specified, it is understood that the spectacle lens 10 shown in figure 2 comprises a central zone, a first peripheral zone and second peripheral zone as disclosed above for the spectacle lens 39 disclosed in figure 3. However, for figure 2, the first peripheral zone is not divided into two intermediary zones 15a, 15b. In figure 2, the arrangement of micro-optical elements has a same pattern over the first peripheral zone. It means that all the micro-optical elements of the first peripheral zone are similar. Typically, here, for the initial optical lens design, the micro-optical elements can be refractive microlenses (for example microsphere) having a size of 1 ,12 mm and having a dioptric power of 1 diopter (D). The density can be set to 50 %.

Figure 4 shows another example of a lens 40 comprised in the pair of eyeglasses according to the present disclosure.

In this embodiment, the first lens 40 is divided in five complementary zones, the central zone 44 and four quadrants zones at 45 degrees defining respectively a first zone

44, a second zone 45, a third 46 and a fourth zone 47. The first zone 44, the second zone

45, the third zone 46, and the fourth zone 47 of the given lens 40 constitute the first peripheral zone 45 of the lens 40. In addition, the four quadrants of given lens 40 comprise each an arrangement of micro-optical elements, that can be the same of one of the quadrants or preferably different of the other quadrants. It be then disclosed an example of the method 100 according to the present disclosure.

The method 100 comprises at least one iteration of the following steps: a) providing E1 a pair of eyeglasses intended to be worn by the subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, b) after a period of time, collecting data E2 relating to the visual behavior and/or the environment of the subject and determining E3 a value of a myopia indicator for at least one eye of the subject, c) controlling E4 the optical lens design of the pair of eyeglasses based on the collected data and the value of the myopia indicator.

It will be disclosed with figures 5-12 an example of an implementation of the method 100 having at least two iterations of the method 100.

In this example, the different iterations are denoted ni with i an index equal to 1 or higher to 1. Preferably, the index i is comprised between 1 and 10, preferably between 1 and 3 (here 1 to 2) to limit the time of the implementation of the method according to the present disclosure.

Thus, it is understood that the first iteration of the method is denoted (n1). However, the method 100 may comprise optional preliminary steps that will be disclosed in the following paragraphs.

First Iteration

Step E01 (n1)

Optionally, in the example shown in figure 5, the method 100 comprises a first step of collecting E01 initial data relating to the visual behavior and/or the environment of the subject.

In the present disclosure, it is meant by data relating to the visual behavior data describing the behavior of the subject, corresponding here to the individual or the wearer, who will wear the pair of eyeglasses obtained by the method according to the present disclosure.

For example, data relating to the visual behavior comprise data carrying an information on the wording visual distance. Typically, it is recorded whether the individual use more often the near vision, and/or the intermediary vision and/or the far vision and/or near-intermediary vision.

Similarly, it is meant by data relating to the visual environment data describing the visual environment of the subject.

For example, data relating to the visual environment can comprise data carrying an information about the lighting environment of the subject, his or her lifestyle. Typically, these data can comprise information on the visual activity of the subject. For example, whether the subject performs a majority of outdoor or indoor activities, or whether his or her works behind a screen or his or her sees a board. In addition, each activity can be associated to a frequent light condition the subject is confronted with (very bright environment, night-time environment, etc.).

Preferably, in the present disclosure, the data relative to the visual behavior and/or the environment of the subject are each associated with a duration to discriminate the data, especially to determine how these data intervene in the daily life of the subject.

In the method 100, these initial data are assessed using a questionnaire.

The questionnaire may be carried out by means of a paper medium or indeed a digital medium (for example: computer, tablet, or smartphone). Alternatively, the questionnaire may be carried out in oral form with a practitioner who asks the questions orally and notes the responses, either on a paper medium, or on a digital medium.

The answers to certain questions may be binary (yes/no), or indeed of the type “never/sometimes/often/always”. Sometimes, the responses may be a score, for example one of between 1 and 5.

In a preferred embodiment, this questionnaire is submitted to the subject by the use of a control unit 60.

In the present disclosure, by control unit, it is meant a computer or a processor or a central processing unit (CPU) or any electronic device allowing to implement a succession of commands and/or calculations. Typically, the control unit comprises a processor, a memory and different input and output interfaces.

Figure 6 shows an example of a questionnaire that can be submitted to the subject using a control unit 60.

In practice, a human-machine interface is used to implement this questionnaire via the control unit 60. This allows the user to directly answer the questions via the humanmachine interface implemented by the control unit 60.

For example, the control unit 60 used in the method 100 is connected to a screen to display 61 the questionnaire to the subject. In addition, this control unit 60 is connected to peripheral electronic devices such as a keyboard 62 and a mouth 63 so that the subject can directly answer the questions by using the control unit 60. The answers can be stored in the internal memory of the control unit or can be stored in an external device, such as on an external memory or a server connected to the control unit.

Typically, here, this questionnaire can assess the visual environment and behavior of the individual when reading or writing on a table (i.e. how far is the front wall when working at home; how far is the board at school; how many hours is he/she working on his/her desk at home/at school; what are the lighting conditions; etc.).

As shown in figure 6, this questionnaire takes the form of pictures 64 that are shown to the subject. Especially here, the screen shows examples of typical categories or classes of environmental situations that are depicted with pictures on the screen of the control unit.

In a preferred embodiment, the classes of environmental situations can comprise at least one of the following classes: home, school, sport activity, home activities, etc.

For example, in figure 6, each class of the environment situation is associated with proximity level that can be rated on a visual analogue scale 65. This analogue scale may have a cursor 66 that can be moved to rank this proximity, for example from "close" to "far". This analogue scale 65 can be ranked into five different levels, where rank 1 corresponds to the closest distance and rank 5 corresponds to the farthest distance.

The visual behavior can be assessed by determining the visual working distance of each class of activity. Thus, for each activity described via the picture, the subject selects the situation that he encounters in his daily life, by selecting the corresponding column and then by estimating a distance by the use of the scale 65.

In addition, each visual activity can be associated with a duration that can be rated with a drop-down list 67 so that the subject chooses one of the durations of this activity.

All the answers are recorded in a memory of the control unit or in an external memory of the connected to the control unit.

Step E02(n1)

After the first step of collecting E01(n1) initial data, the method 100 can comprise a step of determining E02(n1) an optical lens design of a pair of eyeglasses (here corresponding to an initial optical lens design of an initial pair of eyeglasses) based on the initial collected data.

In practice, in this optional step of determining E02, the control unit 60 assesses the visual behavior and/or the visual environment of the subject by analyzing the answered recorded in the memory and then determines an initial optical design of the initial pair of eyeglasses based on the analysis of the answers of the subject.

Typically, the initial optical lens design is selected depending on the working distance of the different classes of the activity and the duration of the activity.

For example, the initial optical lens design depends on the prevalent activities and the working distance associate to this activity.

It is understood that the initial optical lens design of the initial pair of eyeglasses comprises an initial optical design of the first lens of the initial pair of eyeglasses and an initial optical design of the second lens of the initial pair of eyeglasses.

In the present disclosure, the wording “optical lens design” of an optical element comprise at least one of the following elements: the lens design of this optical element, at least one value of a dioptric power, prescription correction, etc.

Thus, in this first step of determining E02, the control unit 60 can select the optical lens design of the first lens and the optical lens design of the second lens by considering the visual behavior and/or the visual environment of the subject determined by the analysis of the answers of the subject.

Thus, optical lens design is adapted to the needs to the subject.

As it is disclosed below, it is understood that the initial lens design of the first lens and the initial lens design of the second lens may be similar or different. Indeed, as explained here, these optical designs are personalized for the subject and thus depend on the subject, his needs.

Step E1(n1)

After these two optional steps, the method 100 comprises the step of providing E1 a pair of eyeglasses intended to be worn by the subject.

In this example, it is provided to the subject a pair of eyeglasses (for instance an initial pair of eyeglasses) based on the initial optical lens design determined previously.

The initial pair of eyeglasses comprises a first lens that is intended to be worn in front the first eye of the subject (for example in front the left eye of the subject) and a second lens is intended to be worn in front the second eye (for example the right eye) of the subject.

Thus, the first lens of this pair of eyeglasses has an optical lens design that corresponds to the initial optical lens design of the first initial lens determined at step E02(n1) and the second lens of the pair of eyeglasses has an optical lens design that corresponds to the initial optical design of the second initial lens determined at step E02(n1).

Thus, it is proposed a pair of eyeglasses having the first lens determined based on the self-reported description of the individual visual behavior and individual environment of the subject and having the second lens determined based on the self-reported description of the individual visual behavior and individual environment of the subject. Therefore, this pair of eyeglasses is personalized for the subject needs.

Of course, if the method 100 does not carry out the steps E01(n1) and E02(n1), in this step of providing E1 (n 1 ) , a standard pair of eyeglasses can be provided to the subject.

For example, if the subject already wears eyeglasses, this standard pair of eyeglasses can have a similar optical lens design of the pair of eyeglasses that the subject wears in his daily life.

Figure 1 shows an example of the pair of eyeglasses that can be provided to the subject.

This pair of eyeglasses comprises a frame 20, the first lens, denoted here 10R, and the second lens, denoted here 10L. Especially, in this example, the frame 20 of this pair of eyeglasses is a smart frame.

In this example, this pair of eyeglasses also comprises at least one sensor device 30.

This sensor device comprises two cameras 31a, 31b positioned on two opposite sides of a fitting surface 21 of a frame 20 of the pair of eyeglasses. Here, the fitting surface of the frame 20 corresponds to the surface of the frame 20 that is oriented towards the field of view of the subject and is therefore oriented perpendicularly to right temple of the frame 20 and perpendicular to the left temple of the frame 20.

As shown in figure 1 , the camera 31a is positioned on a left eyewire 22 of the frame 20, which encases the first lens 10L and the camera 31b is positioned on the right eyewire 23, which encases the second lens 10R.

Each camera is arranged to capture an image of the environment of the subject positioned in the field of view of the associated lens. Therefore, the camera 31a is arranged to capture an image of the field of view of the subject facing the first lens 10L and the camera 31b is arranged to capture an image of the field of view of the subject facing the second lens 10R.

Especially here, the two cameras are arranged to acquire simultaneously an image or a picture. Thus, here, at least two pictures (denoted in the following pair of images) are captured by the sensor device 30. One of the images of the pair of images corresponding to the image acquired by the camera associated to the first lens and the other image corresponding to the image acquired by the camera associated to the second lens.

Preferably, the two cameras may be arranged to acquire the two images when the frame is worn by the subject.

The sensor device 30 also comprises a control unit 32 having a memory arranged to receive each pair of images and to store these images in the memory.

In practice, the cameras 31a, 31b are arranged to capture a pluralities of images per hour.

For example, each camera 31a, 31 b is arranged to acquire at least one image at a frequency of acquisition (for instance acquiring an image every 10 minutes). Typically, this frequency of acquisition can be programmed in advance by a practitioner implementing the method 100. For example, the frequency of acquisition is comprised between 5 minutes and 25 minutes, preferably the frequency of the acquisition is of 10 minutes to acquire enough pictures for the method 100. To control the frequency of acquisition, the at least one control unit 32 may comprise an intern lock 33 which commands the acquisition of the two pictures at the programmed frequency of the acquisition.

This intern lock 33 may be programmed in advance by the practitioner that supervises the method 100.

In addition, in the method 100, the acquisition of the images is performed during a period of time, for instance less than 12 months. In an embodiment, the period of time is comprised between 1 month and 12 months to capture enough pair of images. To this end, the acquisition of the pair of images is made every day and preferably in a similar way. In other words, it means that the frequency of the acquisitions of the pair of images does not change during the period of the acquisition of the images.

In an embodiment, the control unit 32 is arranged to receive the pair of the images of the two cameras 21a, 31b and then to compute from these two pictures, a depth map of the environment of the subject. For instance, the method disclosed by Cornells DOI:

10.1109/CVPR.2005.291 can be used to compute a depth map from two pictures by using an autocorrelation of images.

Figure 7 shows an example of a pair of pictures p1 , p2 captured the cameras 31a, 31b of the eyeglasses shown in figure 1.

These two captured images are sent to control unit 32 that computes a depth map dpi .

In the present disclosure, the depth map dpi is an image of the visual field of view of the subject and contains information relating to the distance of the object comprised in a scene (environment) viewed by the subject.

Typically, the depth map dpi is made of pixels and each intensity of the pixel of this depth map carries information on a distance between the fitting surface of the frame and the part of the object seen on the given pixel.

The values of the intensity are expressed in square diopters. Especially, each distance of the depth map corresponds to a “focal value” and this focal value is inverted to be expressed in diopter (1/f where f corresponds to the focal value of the given camera, here similar for the two cameras). As this intensity is computed over a surface, the values of the intensity are expressed in square diopters.

Thus here, the pair of images (i.e. the two images acquired simultaneously) is used to compute a depth map dpi associated to this pair of images. During the period of time, a plurality of pairs of images may be acquired (or captured). Thus, a plurality of depths maps may be computed by the control unit 32 or provided by the sensor device 30.

Each computed depth map dpi may be internally stored in the eyeglasses, for example in the memory of the control unit 32. In addition, the at least one sensor 30 is configurated to associate with each pair of the acquired images the date and the time of the acquisition of these two pictures and optionally, if a depth map is computed by the at least one sensor 30, the corresponding depth map computed from these two images.

These data are recorded in the memory, for example in a form a list in which each line of the list comprises at last two pictures corresponding to the pictures simultaneously acquired by the cameras 31a, 31b, the date and the time of the acquisition (here comprised in time data) and optionally the associated depth map computed from these two pictures.

Of course, in a variant, the depth map can be computed on an external electronic device (corresponding to an external computing unit) connected to the eyeglasses, especially to the at least one sensor 30.

Therefore, the at least one sensor can further comprise an emitter and a receiver arranged to exchange data with an external electronic device. In practice, the emitter 34 and the receiver 35 use wireless network, for example based on the WIFI technologies, and/or the 2G/3G/4G/5G technology and/or the Bluetooth technology.

For example, the receiver 35 is arranged to receive a request of connection and a request to send the data stored in the memory of the external control unit. After reception of these requests, the emitter 34 is arranged to send to the internal device the stored data, for example the list of the captured images with the date and time of the acquisition and optionally the computed depth maps. Here, the date and the time of each acquisition are also denoted time data.

Therefore, if the depth maps are computed on an external electronic device, the emitter 34 of the at least one sensor device 30 sends the data recorded in the memory, the depth maps being computed by the external device from these recorded data.

Optionally, the at least one sensor device 30 is also arranged to determine a visual field of view of the first eye and a visual field of view of the second eye.

Typically, in the present disclosure, each visual field of view of a given eye corresponds to a space or a zone that a given eye perceives when the subject looks at a specific point of the environment. It meant that the objects positioned in the visual field of view of the given eye are seen by the subject. By see, it is meant that these objects are not blurred.

In the present disclosure, this visual field of view of a given eye may be expressed by a visual cone comprised between 60 degrees (60°) and 80 degrees.

For instance, in that case, the control unit 32 uses the pair of images acquired by the two cameras and computes a difference between the two images by comparing the pixels of the first image and the second image having the same spatial coordinates in the first image and in the second image. This difference gives information on the depth but also on the visual field difference. Indeed, for instance, some objects only appear in one of the images and thus, the control unit 32 will determine from this difference, the field of view of the first eye and the field of view of the second eye.

Of course, it is understood that the visual field of view is determined by considering a plurality of pair of images, for example at least two of three pairs of images to improve the accuracy of the visual field of view of the first eye and the visual field of view of the second eye.

In another embodiment, a binocular picture is computed from each pair of images. Then, the surface of both lenses is projected on this binocular picture. The control unit computes then visual field per eye corresponding here to the projection of the given lens on the binocular picture (figure 10 shows the visual field of views VL and VR associated to the first eye and the second eye). Alternatively or in combination, the control unit may compute the overlapping field, giving us the binocular visual field. In an embodiment, the control unit 32 determines the binocular field of view of the subject based on the visual field of view of the first eye and the visual field of view of the second eye (VB). The binocular field of view corresponds to a zone, or a space positioned at the intersection of the visual field of view of the first eye and of the visual field of view of the second eye.

In another embodiment, the visual field of view may be determined by using a specific device. In that case, the at least one sensor device also comprises a tracker device 36 positioned on the frame 20. Typically, this tracker device 36 is connected to the control unit 32 of the at least one sensor 30.

The eye tacker device 36 is arranged to collect measurements relative to a gaze direction to determine a visual field of view of the first eye and a visual field of view of the second eye.

In practice, the eye tracker device 36 measures and determines from these measurements the visual field of view of the first eye and the visual field of view of the second eye.

The data collected by the eye tracker device 36 and processed from these data are then stored in the memory of the at least one sensor 30.

In practice, the eye tacker device 36 is synchronized with the two cameras 31a, 31b to acquire the gaze direction in a same time of the acquisition of the pair of images. Therefore, each pair of images is associated with gaze direction data comprising the raw data acquired by the eye tracker device 36 (e.g. All the data that have not been processed by the control unit 32) and the processed data determined from these raw data, comprising here to the visual field of view of the first eye, the visual field of view of the second eye and the binocular field of view.

In the present disclosure, it is understood that the pair of eyeglasses provides at this step E1 aims at being worn by the subject during a period of time to acquire (or compute or collect) a plurality of depth maps. Indeed, as each pair of images contains information on the visual field of view of the subject in his daily life, each depth map or each pair of images are thus an indicator of the visual behavior and the visual environment of the subject.

Therefore, using such a smart frame 20 makes it possible to record accurate data on the visual environment and visual behavior of the subject. Especially here, the time and the real visual distances of work, corresponding to the distance of the objects from the wearer meet in his daily life can be deduced from the recorded data.

Of course, in a variant, the pair of eyeglasses provides at this step can standard pair of eyeglasses. By standard, it is meant that this pair of eyeglasses is not a smart frame.

Step E2(n1)

The method 100 comprises the step of collecting E2(n1) data after the period of time.

The period of time can be less than 12 months. In practice, the period of time is comprised between 1 month and 12 months in order to have enough data relating to the visual behavior and the visual environment of the subject.

In this example, the period of time can be of 6 months to have a good compromise between the data acquisition period and the quantity of the recorded data.

In a preferred embodiment, the data collected in this step comprises data acquired by the smart frame disclose above.

Thus, it means that this step of collecting E2 may comprise a step of acquiring simultaneously two images (the pair of images) by the two cameras of the at least one sensor device as explained above. This step of acquiring may be repeated, for instance every 10 minutes (frequency of acquisition), and during the period of time.

In addition, the step of collecting E2 may further comprise a step of computing, by the at least one sensor device, a depth map from the two images acquired simultaneously.

Similarly, the step of collecting may comprise a step of acquiring the gaze direction by the eye tacker device 36 as described above.

Each depth map may be recorded (in a step of recording) in the memory.

Of course, in a variant, the depth map can be computed by an external device of the smart frame. In that case, the step of collecting may comprise receiving or detecting the depth map from the external device.

For example , the recorded data are collected by the use of a control unit (external computer) wireless connected to the pair of eyeglasses disclosed above. Typically, in that case, this control unit first connects to the smart frame by sending a request of connection to the receiver 35 of the at least one sensor device 30. When this connection is achieved, the control unit can freely access to the memory of the at least one sensor device 30 to retrieve the collected data from the memory via the emitter 34.

In the step of collecting, if the collected data does not comprise the depth maps, the external computer or the control unit of the smart frame can compute in this step one depth map per pair of captured images in a same way as explained above.

These data are then stored in a memory of the computer or the control unit collecting the data.

The data stored are then denoted data relating to the visual behavior and/or the visual environment of the subject.

In a variant of this case, when the pair of eyeglasses provides at the step of providing E1 does not comprise smart frame, the step of collecting data E2 is performed by the use of a questionnaire.

This questionnaire may, as explained in step E01 , be carried out by means of a paper medium or preferably by a digital medium (for example: computer, tablet, or smartphone) as shown in figure 6 and explained above.

From this questionnaire, the control unit 60 may determine a depth map per selected activity. In practice, each activity is associated to at least one reference depth map corresponding to an image already stored in the memory of the control unit and selected to represent this activity. In practice, the scene of the reference depth map is like the scene shown to the used during the questionnaire.

The value of the depths of this image may be already determined or may be adjusted depending on the answer of the wearer. For example, the control unit 60 may adapt the different depths to the level of proximities selected via the analogue scale in the questionnaire.

To improve the performances of this variant, the questionnaire allows the user to select different zones in the image of the activity shown to the subject. In that case, the user can select for each zone a proximity level via the analogue scale. The depth map computed by the processing unit can then adapt the depth of the zone of the reference depth map to the value of proximities determined by each zone.

Step E21 (n1)

After retrieving the collected data or after computing the different depth maps, the step of collecting E2(n1) comprises a step of analyzing E21(n1) the retrieved data to determine parameter that will be used in the next steps of the method 100.

To this end, the control unit carrying out this step analyses the collected data, here for example, the different depth maps, to determine at least one of the following elements:

- a value of proximity over time, said value of proximity corresponding to the inverse of an average depth computed from the depth maps. In an embodiment, the average depth may be determined by considering the depths maps associated to the first eye and the second eye;

- a parameter of symmetry between the two lenses of the pair of eyeglasses, said parameter of symmetry being computed from the depth maps associated to the first eye and the second eye.

It will be then disclosed how these different parameters are determined from the collected data.

Value of proximity over time

In practice, the value of proximity over time is determined from the collected data, especially here from the depth map and the time data associated with each depth map.

Typically here, first, the computer computes a distribution of proximities (corresponding to an average depth extract from the collected data) over the day using the collected data during the period of time.

This distribution can be illustrated by using a histogram as described in figure 8 but of course, these data can be recorded in a table.

It will be explained with reference to figure 8 how the value of proximity over time is computed from a first collected data associated to a subject A, a second collected data associated to the subject B and a third collected data associated to a subject C.

For each collected data, the control unit clusters in different classes the depth maps of the collected data as a function of a time of a day by considering the time data, especially, the time of the time data.

For example, here, each class corresponds to an hour of a day and therefore all the depth maps recorded in a same hour of a day are clustered in a same class. Then for each class, the control unit determines an average value of proximity by computing an average depth of all the depth maps of a same class.

This distribution, described here by the histogram of the figure 8, makes it possible to analyze the repartition of the proximities over the day.

For example, it can be seen that the subject A uses on one hand the far vision distance between 7 am and 5 pm but uses in the other hand the near vision distance for later hours comprised between 7 pm and 10 pm.

Same observation can be deduced for the subject C.

However, the subject B uses far vision distance for the majority of the day.

Then, from this distribution, the computer determines the value of proximity over time by computing the average proximity from the values of proximity of all the classes.

Especially here, figure 9 shows that the average proximity over the day for:

- subject A is of 4,94 diopter per hour (D/h), - subject B is of 1 ,87 D/h,

- subject C is of 4,69 D/h.

This average value of proximity over the day corresponds to the proximity over time.

Therefore, it can be deduced that the subject A and the subject C mainly use near-vision distance whereas the subject B mainly uses the far vision distance.

In order to improve the accuracy of the value of proximity over time, the control unit used can work in specific zones of the collected data, especially here in specific zones of the computed depth maps, to compute the value of proximity over time.

In an embodiment, the value of proximity over time can be measured based on the gaze direction of the subject. Thus, the distribution of the proximity over the day (or time) can be measured based on the gaze direction of the subject thanks to the eye tracker device 36.

In practice, in the collected data, the visual field of view of a given eye delimits a zone in each depth map and can be illustrated by a contour of a geometric form in each depth map.

Typically, the computer projects on each depth map, the visual field of view of the first eye and the visual field of view of the second eye.

For example, in figure 10, the visual field VL of view of the first eye and the visual field of view of the second eye VR are projected on the depth map dp2.

In practice, the distribution of proximity over day can only be computed from the pixels comprised in the binocular visual field of view VB of the subject (corresponding to a part of the intersection of the visual field VL of view of the first eye and the visual field of view of the second eye VR). In other words, the control unit selects, in each depth map, a portion of a given depth map comprised in the cercle representing the binocular visual field VB of view of the subject, the other part of the given depth map being excluded from the computation of the distribution of proximity over time (or day). Then, the computation of the value of proximity over time is performed as explained above by only using the information of the depth maps comprised in the binocular visual field of view of the subject

In another embodiment, the value of proximity over time can be computed for each eye by considering the visual field of view of the first eye and the visual field of view of the second eye. In that case, two values of proximity over time are computed, one associated to the first eye and another associated to the second eye. To this end, a first distribution of proximity over day can be computed from pixels comprised in visual field of view of the first eye and a second distribution of proximity over day can be computed from pixels comprised in visual field of view of the second eye as explained above. Then, the computation of the value of proximity over time is carried for each distribution of proximity over day (i.e. for the first distribution of proximity over day and for the second of proximity over day).

In another embodiment, the assessment of the proximity over time can be done on specific zones by considering the optical lens design of the given lens. For example, when the initial optical lens design of a given lens comprises different arrangement of micro- optical elements as shown in figure 3 or 4, the assessment of the proximity over the time can be performed in each zone having an arrangement of micro-optical elements. For instance, for the embodiment of figure 3, this assessment is performed in the first preliminary zone and in the second preliminary zone. For the example of figure 4, this evaluation of proximities is determined in each quadrant (left, right, up, down).

Determining the proximity over time in several zones of the lens improve the accuracy of the method 100. For example, in case of the quadrants, other data can be computed, for example by calculating the differences of the proximity over time between the different zones.

Parameter of symmetry

The parameter of symmetry may be based on value of proximity over time previously determined, for instance, based on value of proximity overtime associated to the first eye and on value of proximity over time associated to the first eye.

The control unit used at this step is also configured to determine a parameter of symmetry based on the collected data, especially based on the computed depth maps and the visual field of view of the first eye and the visual field of view of the second eye.

In practice, for each depth map, the control unit compares the values of the depths (of a given depth map) comprised in the visual field of view of the first eye with the values of the depths comprised in the visual field of view of the second eye.

To do so, in this embodiment, the control unit uses the value of proximity over time determined for the visual field of view of the first eye and uses the value of proximity over time determined for the visual field of view of the second eye described above to determine a ratio of proximity between the value of proximity over time determined for first eye and the value of proximity over time determined for the second eye, said ratio corresponding to the parameter of symmetry.

In practice, the control unit (or computer) divides, for example, the value of proximity over time of the first eye by the value of proximity over time of the second eye (or inversely the value of proximity over time of the second eye by the value of proximity over time of the first eye) and then compares this ratio to a threshold value.

For instance, the threshold value is a range of values comprises between 0.9 and 1.1. Indeed, a perfect symmetric corresponds to a ratio of one. However, as the ratio is computed from measurements, a level of tolerance is considered in this embodiment. Thus, on one hand, if the computed ratio is comprised between 0.9 and 1.1 , it means that the subject has a symmetric posture. On another hand, if the computed ratio is lower than the range of values disclosed above or higher than the range of value disclosed above, it means that the subject has an asymmetric posture.

In one embodiment, the threshold is equal to 1.

Step E3(n1)

The method 100 also comprises a step of determining a value of a myopia progression indicator for at least one eye of the subject. Typically, this step is carried out by the control unit used in the method 100 which can determine the value of a myopia progression indicator for the first eye and/or for the second eye of the subject.

By myopia progression indicator, it is meant a parameter that allows assessing the progression of the myopia over time. In practice, for the first iteration of the step of determining E3(n1), the determined value of the myopia progression indicator is a first determined value of this indicator to have a reference point.

Typically, for each eye, the myopia progression indicator comprises at least one of the following elements: a value of a prolateness indicator, a value of an axial length indicator, a value of a refraction indicator.

Prolateness indicator

In the present disclosure, it is thus possible to assess the efficiency of a myopia solution by following the eye shape evolution.

It has been observed and confirmed that monitoring the prolateness of at least one eye of the subject provides a good indication of the efficiency of a myopia control solution at an individual level.

The prolateness of one eye may be characterized by determining the shape of the retina of the eye of the person (subject) at least over a given angular zone of the retina of the person. The given angular zone is of at least 5° on the nasal part, for example at least 10° on the nasal part, preferably at least 15° on the nasal part, and of at least 5° on the temporal part, for example at least 10° on the temporal part, preferably at least 15° on the temporal part.

The selection of the given annular zone depends on the value of the period of time. In practice, if the period of time is comprised between 1 month and 9 months (excluded), the prolateness indicator is determined over the nasal region of the retina. In contrast, if the if the period of time is equal to 9 months or higher than 9 months, the prolateness indicator is determined over the temporal region of the retina of the subject.

Indeed, it has been observed that over a long period of time, typically greater than 9 or 10 months and smaller than 36 months, the prolateness indicator of the eye in the temporal region of the retina is more discriminating than the prolateness indicator of the eye on the nasal region.

In practice, the prolateness parameter (or indicator) of one eye is determined, for example here for the first eye of the subject. Typically, the document WO2022136192A1 describes an example of how the prolateness indicator of one eye is determined.

First, in the method 100, one can determine data pertaining to an ocular shape of a given eye using a measuring device and from this data one can determine the prolateness indicator.

The data about the ocular shape can be obtained with different measurement methods such as:

- (Relative) peripheral refraction - for example 30° deg temporal, 15° deg temporal, fovea, 30° deg nasal, 15° deg nasal;

- (Relative) peripheral axial length - for example 30° deg temporal, 15° deg temporal, fovea, 30° deg nasal, 15° deg nasal;

- optical coherence tomography or OCT - for example 6 mm b-scan

- Magnetic resonance imaging or MRI;

For example, a typical way of acquisition of the ocular shape data using axial length or refraction is done according to naso-temporal b-scan (two-dimensional crosssection).

Mathematically, the prolateness can be for example quantified by fitting the posterior eye shape data by a quadratic function.

The quadratic function may be for example, f(x) = -a*(x+b)2 + c where “x” is visual field angle, “a” quantifies the prolateness, “b” factor specifies the x position (i.e., retinal position) of the peak of the function, and “c” is the y position (i.e. best fitting central axial length).

For example, a specific procedure for obtaining the prolateness is to find such a, b, and c parameters to minimize the sum of squared residual, i.e., the difference between an observed value, and the fitted value provided by the quadratic function, commonly referred to as least squares analysis, over a number of iterations, for example 1000. The best fitting a, b, and c parameters, i.e., the sum of least squared residuals across the iterations is the smallest, are considered best representatives of the retinal shape and the term “a” is taken as an indicator of the prolateness of the eye.

According to an embodiment of the disclosure, the prolateness indicator may be determined based on a 3D measurement of the retina of said at least one eye of the person.

The ocular shape data can be acquired at different locations or orientations across the retina for example by denser sampling or using an advanced imaging modality such as optical coherence tomography or OCT or MRI system. In case of such continuous retinal shape data, the retinal shape parameters can be calculated by the methods described previously. Furthermore, imaging techniques such as optical coherence tomography allow for volume data acquisition that allow for calculation of retinal prolateness maps.

Of course, other methods to determine the prolateness indicator can be used. These other methods are disclosed in document WO2022136192A.

To improve the accuracy of the method 100, in step E3, a prolateness indicator can be computed for each eye of the subject. Document WO2022136192A1 also describes an example on how to determine a prolateness indicator for each eye of the subject.

In practice, the prolateness indicator for the second eye is determined as the prolateness indicator of the first eye.

Thus, in that case, it is determined the value of the prolateness indicator of the first eye and the value of the prolateness indicator of the second eye.

In addition, although that the prolateness parameter is described, it is understood that the refraction indicator and/or the axial length indicator can be determined as disclosed in the document WO2022136192A. These latter parameters can be determined in addition or alternatively to the prolateness parameter.

For instance, it can be determined the value of the axial length of the first eye and the value of the axial length of the second eye and/or the value of the of a refraction of the first eye and the value of the of a refraction of the second eye.

These latter indicators can be determined as explained above or by performing a naso-temporal b-scan (two-dimensional cross-section) of the shape of the retina.

Step E4(n1)

After having analyzed the collected data and determined a value of myopia progression indicator, the method 100 comprises a step of defining E4(n1) the optical lens design of the pair of eyeglasses based on the collected data and the value of the myopia indicator. This optical lens design may be a new (or final) optical lens design of the pair of eyeglasses compared to the optical lens design (here the initial lens optical design) provided at the step of providing a) (E1 (n1 )) .

Thus, it means that in this step of defining E4(n1), the collected data, for instance the at least one computed depth map or data extract from this at least one depth map, are combined with the value of the myopia progression indicator to determine the optical lens design of the pair of eyeglasses.

As it will be disclosed, in this step, the collected data and the value of the myopia progression indicator may be used to determine at least one feature of the arrangement of the micro-optical elements in the first lens and/or at least one feature of the arrangement of the micro-optical elements in the second lens. Thus, the optical lens design of the pair of eyeglasses may depend on the at least one determined feature of the of the arrangement of the micro-optical elements of first lens and/or the at least one determined feature of the arrangement of the micro-optical elements of second lens.

In practice, the optical lens design of the pair of eyeglasses is determined based on the determined value of the myopia indicator and the analyzed collected data, comprising for example the parameter of symmetry and/or the value of the proximity over the time.

In addition, an additional parameter can be used to determine the optical lens design of the pair of eyeglasses. This additional parameter may comprise a level of discomfort, for example by questioning the subject to determine if he felt a visual discomfort during the period of time.

In this step, it is understood that the optical lens design of the pair of eyeglasses comprises the optical lens design of the first lens and the optical lens design of the second lens.

In this step, the optical lens design used previously (at the step of providing a)) is changed or adapted to the collected data and/or the value of the myopia progression indicator.

In addition, it is understood that the optical lens design of each pair of eyeglasses comprises features on the arrangement of micro-optical elements of each lens.

To obtain a method less time consuming, only one optical lens design of a lens can be determined, for example by only determining the value of the myopia progression indicator for the first eye and by using in this step the value of the proximity over time and the value of the myopia progression indicator for the first eye. In that case, the method 100 is configured to attribute the same optical lens design to the other lens.

Of course, to determine a more personalized pair of eyeglasses, the method 100 determines the optical lens design of the first lens and the optical lens design of the second lens.

To this end, for one of the lenses (here for example the first lens), the optical lens design of the first lens can be determined by the value of the myopia progression indicator of the first lens and the value of the proximity over time and/or the parameter of symmetry.

Similarly, for the second lens, the optical lens design of the second lens can be determined by the value of the myopia progression indicator of the second lens and the value of the proximity over time and/or the parameter of symmetry.

In the following, it will be disclosed more precisely how the optical lens design of one lens is determined.

In the present disclosure, this step aims at improving the vision of the subject, for example by determining if the images are improved or deteriorated in the prescription plane. In one embodiment, this can be achieved by adapted at least one feature of all the micro-optical elements or a part of the micro-optical elements comprised in the arrangement of the micro-optical elements of the given lens to improve the vision quality of the subject. To improve the readability, the micro-optical elements that will see their features changed will be denoted selected micro-optical elements. However, it is understood that the wording “selected micro-optical elements” can refer to a part of the micro-optical elements of the arrangement of micro-optical elements. Thus, as this part of micro-optical elements means at least one micro-optical element (pertaining to a single micro-optical element or a plurality of micro-optical elements in the arrangement of micro-optical element), the “selected micro-optical elements” can also correspond to at least one micro-optical element.

In practice, to this end, it is determined whether the at least one feature of the selected micro-optical elements is kept or changed.

Typically, the step of defining comprises a step of comparing E41(n1) the value of the myopia progression indicator determined previously to a threshold value.

Then, depending on the comparison, the step of defining E4(n1) comprises a step of changing E42(n1) the at least one feature of the selected micro-optical elements comprised in the arrangements of the micro-optical elements of at least one of the lenses of the pair of eyeglasses or keeping the at least one feature of the selected micro-optical elements of at least one of the lenses of the pair of eyeglasses.

In practice here, if the value of the myopia progression indicator reaches the threshold value, for example if it is lower or equal to the threshold value or if it is higher or equal to the threshold value, the at least one feature of the selected micro-optical elements of the given lens can me modified.

In the step of changing, the value of at least one optical feature of the selected micro-optical elements is changed with another value, for example by decrementing or incrementing the value of the optical feature of at least 0.1 , preferably by at least 0.5 compared to the initial value of the feature of the selected micro-optical elements of the first optical lens design.

As it is the first iteration of the method 100, the step of defining can use a table that defines a pattern of micro-optical elements as a function of the value of the myopia progression indicator.

Thus, it means that the threshold value may be a predefined value of the table.

For example, figure 12 and figure 13 define each an example of a table (stored in a memory of the control unit used) allowing to determine the features of the selected micro-optical elements when the myopia progression indicator corresponds to the prolateness indicator. Typically, this table defines indications to select the at least one optical feature of the selected micro-optical elements. For instance, this at least one optical feature can comprise the power and/or the density and/or the size of the micro-optical elements. Only one of these features can be compared.

Preferably, in each step of determining, the at least one feature, that is compared, is selected in this order: the density or the number of micro-optical elements, the dioptric power or the focal length, the diameter (or size), the position, the geometry and the refractive, diffusive, or diffractive optical function of the micro-optical elements. One can also determine only a part of the features of the previous list, the other optical features staying unchanged in the method 100.

For example, in this embodiment, the step of defining is configured to first compare the density or the number of micro-optical elements using the table.

In figure 12, it can be seen that when the prolateness indicator has a value comprised between 5 mm/deg and 10 mm/dg (here corresponding to a threshold value), the arrangement of micro-optical elements is defined to have a density higher than 50 and lower than 70%. For example, the density can be comprised between 55% and 60 %.

In addition, one can also consider the initial features of the arrangement of micro- optical elements used at the step of providing of this current iteration, corresponding here to the step E1(n1). Thus, it means that this step of defining (especially here changing or keeping the feature) may also depend on the initial optical lens design.

For instance, here, as the density of the arrangement of the micro-optical elements of the initial optical lens design has a density that matches with the information described in the table, it can be decided to keep the value of the density of the arrangement of the micro-optical elements.

Thus, it means that if the value of selected feature (here the density) defined in the initial lens design matches with the data of the table, another optical features can be selected by the method 100.

Preferably, dioptric power and/or the density and/or the size of the micro-optical elements of the arrangement of micro-optical elements can be modified depending on the initial optical lens design determined at step E01. Indeed, these features are those having the greatest influence on the vision quality.

It is also understood that the density can be kept. For instance, if the density of the initial lens design of the first lens was of 55 %, by using figure 13, the value of the dioptric power of the micro-optical elements of the arrangement of micro-optical elements can be modified instead of the value of the density of the micro-optical elements.

Here, by using this table, the dioptric power can be selected to be comprised between 5 D and 7 D. As in the initial lens design of the first lens the micro-optical elements have a dioptric power of 1 D, this dioptric power is incremented of at least 4 D to be equal to 5 D. It is also understood that at the first iteration of method 100, only a single feature can be modified (here the density). Therefore, the method 100 is configured, in the next iteration (here the second iteration n2), to change another feature, for example the dioptric power, by using the table illustrated in figure 13.

Thus, in one embodiment, it means that, depending on the comparison, the adaptation (adjustment) of the features of the selected micro-optical elements depends on the value of the myopia progression indicator and the optical lens design of the pair of eyeglasses provided at the step of providing of the current iteration.

Especially in the present case, as the density is kept, the value of the dioptric power and/or the size of the micro-optical elements can be modified. This modification can consider the table used in this step, for example, by comparing on one hand the information on the density and/or on the size defined for this value of the given prolateness indicator with the initial optical lens design of the given lens.

Nerveless, in one embodiment, the step of changing can be also based on the given collected data.

Typically, the step of defining comprises a step of comparing E43(n1) the collected data or element extract from the collected data to a threshold value.

Then, depending on the comparison, the step of defining E4(n1) comprises a step of changing E44(n1) the at least one feature of the selected micro-optical elements comprised in the arrangements of the micro-optical elements of at least one of the lenses of the pair of eyeglasses or keeping the at least one feature of the selected micro-optical elements of at least one of the lenses of the pair of eyeglasses. It will be disclosed an implementation of these steps.

It is understood that although that the comparison with the myopia progression indicator does not lead to a modification of the optical features of a part of the selected micro-optical elements, the method is also configured to adapt the selected micro-optical element of the given lens to the collected data, especially here, to the value of the proximity over time and/or the parameter of symmetry previously determined.

For example, when only the optical lens design of one lens is determined, only the value of proximity over time is analyzed. In a preferred embodiment, the dioptric power of the arrangement of the micro-optical elements is adapted to the value of proximity.

To do so, the step of defining comprises the step of comparing E43(n1) the value of the proximity over time determined previously to a threshold value.

Then, depending on the comparison, the step of defining E4(n1) comprises the step of changing E44(n1) the at least one feature of at least a part of the micro-optical elements comprised in the arrangements of the micro-optical elements of at least one of the lenses of the pair of eyeglasses or keeping the at least one feature of the arrangement of micro-optical elements of at least one of the lenses of the pair of eyeglasses.

Typically, for the value of proximity, the threshold value can be equal or higher than 2, preferably higher than 3.

In that case, if the value of proximity is lower than 3, it means that the value of proximity is low. In contrast, if the value of proximity is higher than 3, than it means that the value of proximity is high.

In addition, the additional parameter relative to the repartition of the proximity over the day can be used.

Especially here, the control unit can compute (step E45(n1) determination of an additional parameter) the standard deviation (as additional parameter), denoted s of this distribution to determine whether the value of proximity over the time (determined from this distribution) is homogeneous in time or whether it is heterogeneous in time.

Then, the control unit determines the percentage of the values of the proximity over the day comprised in a range of values based on this additional parameter, this range of values based on this additional parameter being defined as k [- value of the additional parameter ; + value if the additional parameter] with k an integer equal to or higher than 1.

For example, it is compared whether at least 50 percent of the values of the proximities are comprised in the range of values comprised between [ - s; +s], when k is equal to 1.

If the values of proximity over the day satisfy this criterion, it means that the values of proximity over the day are homogeneous or quite homogeneous. In that case, only one lens design is selected. In other words, it means that the selection of the optical feature depends only on the value of the proximity over time determined previously and here described in figures 8 and 9.

In the present example, subjects B and A satisfy this criterion, the control unit selects only one optical design for this subject and this selection depends on the value of the proximity over the day determined for the given subject.

For instance, as the subject B uses the near vision, the feature that will be changed is adapted to this vision, by for example incrementing or decrementing the feature, here for example, the dioptric power of the micro-optical elements, to improve the visual acuity of the subject but by limiting the myopia control signal.

As the subject A uses the far vision or intermediate vision, the feature that will be changed is adapted to this vision, by for example incrementing or decrementing the feature, here for example, the dioptric power of the micro-optical elements, to increase the myopia control signal compared to myopia control signal obtained with the initial optical lens design previously provided.

Subject C does not satisfy the criterion, therefore the control unit selects at least two optical lens designs based on the distribution previously determined. For instance, the control unit clusters in different groups the proximity over the day, for example by regrouping, on one hand, the values of the proximity over the day that satisfy the criterion in a same class and on the other hand the values of proximity that does not satisfy the criterion in at least another class. It is understood that the number of classes determined for the values of proximity that satisfy the criterion depends on the homogeneously of these values. In other word, this number is selected so that all the values of the proximity of a same class are homogenous (e.g. they satisfy the criterion defined above).

For instance, it can be seen that the value of the proximity can be clustered in two classes. Thus here, the control unit selects two optical designs based on these two classes, by providing:

- a first optical lens design between 7 am and 6 pm keeping or limiting the myopia control signal compared to the initial optical lens design;

- a second optical lens design between 6 pm and 10 pm providing a higher myopia control signal compared to the initial optical lens design.

For instance, if the feature is the dioptric power, the dioptric power of the micro- optical elements of the optical lens design determined for subject B (denoted P2) will be higher than the dioptric power of the micro-optical elements of the optical lens design determined for subject A (P1) but lower than the dioptric power of the micro-optical elements of the second optical lens design determined for subject C (P3). The first optical lens design can be equal to the optical lens design provides for subject A.

In one embodiment, the method is also configured to adapt the selected micro- optical elements of the given lens to the parameter of symmetry.

Indeed, the control unit checks whether the ratio defined above reaches the threshold value.

For instance, in this example, the threshold value is equal to 1.

If the ratio is equal or lower than the threshold, the control unit selects a single optical lens design for the first lens and the second lens. In other word, it means that the optical lens design of the first lens will be se same as the optical lens design of the second lens.

In the other hand, If the ratio is higher than 1 , the control unit selects a specific optical lens design for the first lens and a specific optical lens design for the second lens.

For example, it means that, the lens optical lens design of the first lens can have a value of at least one feature of the micro-optical elements of the first lens that differs from the value of the at least one feature of the micro-optical elements of the second lens. For instance, it means that the density or the number of micro-optical elements, and/or the dioptric power or the focal length, and/or the diameter (or size), the position, and/or the geometry and the refractive, and/or the diffusive, or diffractive optical function of the micro- optical elements of the first lens differs from the density or the number of micro-optical elements, and/or the dioptric power or the focal length, and/or the diameter (or size), the position, and/or the geometry and the refractive, and/or the diffusive, or diffractive optical function of the micro-optical elements of the second lens.

In one embodiment, the implementation of the step of determining depends on the optical lens design (here the initial optical lens design) provided at the step of providing E1 . This is for instance used when the lens comprises at least two different arrangements of micro-optical elements as illustrated in figure 3 or in figure 4.

In that case, it is understood that the first lens and/or the second lens may have an optical lens design that varies spatially on the lens. It means that the lenses may have zones in which at least one feature of the optical elements comprised in these zones is different.

In that case, the step of determining E4 is repeated for each zone of the lens.

Other iterations

When the step of defining ends, the steps of providing E1 , collecting E2 and determining E3 and the step of defining E4 can be reiterated in a new iteration of the method 100, denoted n2. Only the differences between the two iterations will be disclosed.

In that case, the pair of eyeglasses provided at the step of providing E1 (n2) has an optical lens design based on the optical lens design of the pair of eyeglasses defined at the step of defining of the previous iteration (i.e. determined at the end of the step of defining E4). In other words, it means that, at the step of providing E1(n2), the first lens of the pair of eyeglasses has an optical lens design that corresponds to the optical lens design of the first lens determined at the step of defining E4(n1) and the second lens of the pair of eyeglasses has an optical lens design that corresponds to the optical lens design of the second lens determined at the step of defining E4(n1).

Thus, it is understood that the step of providing E1(n2) may implicitly comprise a step of manufacturing:

- the first lens based on the optical lens design of first lens determined in the step of defining of the previous iteration, and

- the second lens based on the optical lens design of second lens determined in the step of defining of the previous iteration.

The step of collecting E2(n2) of the current iteration is implemented in a same manner as the step of collecting E2(n1) of the previous iteration. However, in that case, instead of using the initial lens design of the pair of eyeglasses, it is optical lens design determined at the previous step of defining E4(n1) which is used.

Therefore, the period of time may be similar, for example it is of 6 months. Of course, the period of time of the collected data may be modified. In that case, it depends on the new pair of eyeglasses provided at the step E1(n2).

In another embodiment, the pair of eyeglasses provided at the step E1(n2) can be selected in a catalogue of existing eyeglasses.

Similarly, for the new step of determining E3(n2), the threshold depends on the value of the myopia progression indicator determined at the previous iteration. For instance, it is checked whether the myopia progression indicator has changed between the first iteration and the second iteration, by for example, comparing the current determined myopia progression indicator with the myopia progression indicator determined at the previous step.

For example, in figure 11, it can be seen that the myopia progression indicator (corresponding here to the prolateness indicator) of the subject 1 has increased whereas the myopia progression indicator of the subject 2 has decreased.

If an increase is determined, the at least one feature of the selected micro-optical elements will be modified in the step of defining E4(n2) to increase the myopia control signal. For example, this can be achieved by increasing the density or the number of micro- optical elements in the arrangement of micro-optical elements in the given lens. Of course, in addition or in alternative, other features can be modified, by for example increasing the dioptric power of the micro-optical element and/or the size of the micro-optical elements.

On the other hand, if a decrease is determined, the at least one feature of the selected micro-optical elements will be selected in the step of defining E4(n2) to decrease the myopia control signal, for example by decreasing the density or the number of micro- optical elements in the arrangement of micro-optical elements in the given lens. Of course, in addition or in alternative, other features can be modified, by for example decreasing the dioptric power of the micro-optical elements and/or the size of the micro-optical elements.

Of course, as explained above, other myopia progression indicator can be used, for instance the axial length indicator and/or the refraction indicator.

As for the myopia progression indicator, the control unit checks the evolution of one of these indicators, for instance if it has increased or not and as a function of the evolution, the feature of the selected micro-optical elements are adapted or kept.

At the end of the step of defining of the last iteration, a final optical lens design of the pair of eyeglasses is determined. The final lens design of the pair of eyeglasses is then used to manufacture the pair of eyeglasses which is then intended to be worn by the wearer to help improving his vision. In that case, the final optical lens design of the pair of eyeglasses becomes the optical design of the pair of eyeglasses which is manufactured and worn by the wearer.

Therefore, the method 100 comprises a final step of providing E5(n) a pair of eyeglasses based on this final optical lens design of the pair of eyeglasses. Preferably, two iterations of the method 100 are performed, limiting the time of the implementation of the method (and the cost of this implementation) while providing a pair of eyeglasses customized as a function of the needs of the subject, the visual comfort of the subject and/or the myopia evolution of the subject. Device

The invention also aims at defining a pair of eyeglasses 1000 comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, said pair of eyeglasses having an optical lens design determined with the method 100 disclosed above,

For example, this pair of eyeglasses is similar to the pair of eyeglasses shown in figure 1 and disclosed above. It is understood that each step that can be computed by a control unit can be carried out by the control unit 32 of the pair of eyeglasses according to the present invention. Especially here, the steps E2, E21, E4 disclosed above can be implemented by the control unit of the pair of eyeglasses.

Claims

1. Method for defining an optical lens design of a pair of eyeglasses intended to be worn by a subject, said method comprising at least one iteration of the following steps: a) providing a pair of eyeglasses intended to be worn by the subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, b) after a period of time, collecting data relating to the visual behavior and/or the environment of the subject and determining a value of a myopia progression indicator for at least one eye of the subject c) defining the optical lens design of the pair of eyeglasses based on the collected data and the value of the myopia progression indicator.

2. Method according to claim 1, wherein the arrangement of micro-optical elements of each lens of the pair of eyeglasses comprises at least one feature, the step of defining comprising:

- comparing the value of the myopia progression indicator to a threshold value,

3. Method according to claim 2, wherein the step of changing is also based on the given collected data.

4. Method according to claim 2 or claim 3, wherein the step of defining further comprises:

- checking whether a parameter based on the visual comfort satisfies a criterion,

- if the criterion is not satisfied, said step of changing being also based on the parameter based on the visual comfort.

5. Method according to any one of claims 1 to 4, wherein the arrangement of micro-optical elements of each lens comprises at least one of the following features:

- density of the micro-optical elements;

- dioptric power of the micro-optical elements;

- geometry of the micro-optical elements;

- refractive, diffractive or diffusive optical function of the micro-optical elements; - size of the micro-optical elements;

6. Method according to any one of claims 1 to 5, wherein the method further comprises:

- after the step of defining c), reiterating steps a), b) and c) in a new iteration of the method, said pair of eyeglasses provided in the new iteration of the method being based on results of the step of defining obtained in the previous iteration of the method.

7. Method according to any one of claims 1 to 6, wherein the period of time is comprised between 1 month and 12 months.

8. Method according to any one of claims 1 to 7, wherein the method comprises, before a first iteration of the method: a01) collecting initial data relating to the visual behavior and/or the environment of the subject, the optical lens design of the pair of eyeglasses provided at step a) of the first iteration of the method being based on the initial collected data.

9. Method according to claim 8, wherein at least one of the steps of collecting comprises a step of submitting the subject to a questionnaire relating to the visual behavior and/or the environment of the subject, the responses to the questions of this questionnaire being comprised in at least one of the following elements:

- the initial collected data,

- the collected data.

10. Method according to any one of claims 1 to 9, wherein in the step of collecting, measurements relating to the visual behavior and/or the environment of the subject are collected by means of at least one sensor device positioned on the frame of the pair of eyeglasses.

11. Method according to claim 10, wherein the at least one sensor device comprises two cameras positioned on two opposite sides of a fitting surface of a frame of the pair of eyeglasses oriented towards the field of view of the subject, each camera being associated to one of the lens of the given pair of eyeglasses, said at least one sensor device being arranged to provide at least one depth map of the environment positioned in the visual field of view of the subject from two images acquired simultaneously by the two cameras, said at least one depth map being comprised in the collected data.

12. Method according to claim 11 , wherein the at least one sensor is arranged to provide at least six depth maps per hours.

13. Method according to any one of claims 11 to 12, wherein in the step of collecting, depth maps are provided, after the step collecting, the method comprises a step of analyzing the collected data by a computer, said step of analyzing providing at least one of the following elements:

- a value of proximity over time, said value of proximity corresponding to the inverse of an average depth computed from the depth maps;

- a parameter of symmetry between the two lenses of the pair of eyeglasses, said parameter of symmetry being computed from the depth maps associated to the first eye and the second eye, said at least one element being used in the step of defining c).

14. Method according to claim 13, wherein, for each lens, a plurality of values of proximity are determined based on a visual field of view of the first eye, on a visual field of view of the second eye, and on an average depth map computed from the depth maps, each value of a plurality of values of proximity being associated to a specific zone of a given lens of the pair of eyeglasses.

15. Pair of eyeglasses intended to be worn by a subject, said pair of eyeglasses comprising a first lens intended to be worn in front a first eye of the subject and a second lens intended to be worn in front of a second eye of the subject, each lens of the pair of eyeglasses comprising: i) a refraction area based on a prescribed refractive power, and ii) an arrangement of micro-optical elements, said pair of eyeglasses having an optical lens design determined with the method according to any one of claims 1 to 14, said pair of eyeglasses comprising a frame, and at least one sensor device positioned on the frame of the pair of eyeglasses and arranged to collect measurements relating to the visual behavior and/or the environment of the subject, said sensor device comprising a control unit to perform steps b) and c) of the method according to any one of claims 1 to 14.