Anti-eye fatigue contact lenses and the process for producing such lenses

Abstract

ANTI-VISUAL FATIGUE CONTACT LENSES AND A METHOD FOR PRODUCING SUCH LENSES. One aspect of the invention relates to a contact lens intended for a target subject with at least one ametropia other than presbyopia and heterophoria in near vision, having a concave inner surface and a convex outer surface and having the following parameters: a first zone covering a central disc having a diameter and a first optimized optical power profile; a second annular zone surrounding the first zone having an inner diameter, an outer diameter such that and a second optimized optical power profile such that; a third annular zone surrounding the second zone having an inner diameter, a second outer diameter such that and an optimized optical power profile such that;a fourth annular zone surrounding the third zone having a third internal diameter, a third external diameter such that and an optimized power profile such that . Figure to be published with the abbreviation: Figure 2;

Description

Title of the invention: ANTI-EYE FATIGUE CONTACT LENSES AND A METHOD FOR PRODUCING SUCH LENSES TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates generally to contact lenses used for correcting refractive errors of the visual system in humans. It relates more particularly to contact lenses designed to reduce eye strain.

[0002] The invention finds applications, in particular, among adult wearers, ametropic non-presbyopic, presenting heterophoria in near vision, and who experience visual fatigue during prolonged demands on their visual system, particularly in near vision. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Developing high-performance systems for correcting refractive errors in the human visual system requires overcoming three essential types of technical difficulties. First, designing a system of excellent optical quality, that is, one with optical properties (optical power, aberrations, etc.) that are as suitable as possible for correcting specific refractive errors. Second, perfectly mastering the manufacturing process to reproduce as faithfully as possible the optical characteristics determined during the design phase, for example, by precisely obtaining a specific curvature or surface finish. Third, proposing a system capable of adapting as effectively as possible to environmental factors.Indeed, such an optical system, particularly in the case of contact lenses, is not an isolated system since it is designed to interact with biological systems (related to the human eye). These biological systems are themselves adaptive, meaning they are subject to feedback loops and changes in their characteristic parameters based on external, generally environmental, factors. It is therefore desirable that such an optical system be able to track these changes as closely as possible.

[0004] This last technical difficulty is all the more critical given that, in the lifestyle of contemporary societies, the demands (more or less intense) on the visual system are becoming increasingly numerous and potentially lead to changes in this system over time. Indeed, a very large number of widely used technologies, for both professional and non-professional purposes, demand intense and / or prolonged use on the visual system. This is the case, for example, with intelligent communication tools that use, in particular, still images or animated, such as for example a computer screen, a tablet or a smartphone, a 3D visualization system, etc. Given the current uses of these types of devices, the user may be required to look at the screen of these devices, especially at close range, for very long periods of time.

[0005] These stimuli can be of different kinds and correspond, on the one hand, to the biological effects of stimuli related to electromagnetic radiation (in the wavelength range of so-called visible radiation, but also possibly in ranges undetectable by the human eye, such as ultraviolet or infrared radiation). On the other hand, these stimuli can be physiological. In particular, they can stimulate the various components of the visual system, and especially the eye, such as the components of the eyeball, namely the cornea, the lens, and the retina. This is also the case for the oculomotor system, which includes the six extraocular muscles, innervated by the three oculomotor nerves, the junction with the limbus, and the eyelids (tarsus and orbicularis oculi muscle), whose physiological blinking allows the tear film, secreted by the lacrimal glands, to spread across the surface of the cornea.

[0006] Such stresses, particularly when intense and / or prolonged, can cause adverse effects. For example, Computer Vision Syndrome (CVS) is a set of ocular and extraocular symptoms associated with the prolonged use of electronic devices with a display screen. It is associated with asthenopic symptoms, i.e., eye strain, but also with accelerated progression of myopia, blurred vision, dry eyes, redness of the eyes, and musculoskeletal symptoms such as back pain, or neck or shoulder pain. These phenomena are, for example, described in the BMJ Open Ophthalmol article. 2018;3(l):e000146 which classifies the symptoms into two categories: those related to dry eye in particular (called internal eye discomfort) and those related to accommodation (called external eye discomfort).

[0007] Furthermore, recent epidemiological studies (reported in particular in the article Ophthalmic Physiol Opt., 2016;36(2): 112-9) show that contact lens wearers are more likely to suffer from eye strain, particularly associated with fatigue of the extraocular muscles, than non-wearers. Other studies have also demonstrated that this symptomatology is significantly more pronounced in myopic subjects who benefit from correction with contact lenses (Int J Health Sci (Qassim) 2017;1 1(5):17-19). Finally, other scientific studies have also demonstrated that despite the use of refractive corrections, many screen users still suffer from eye strain, headaches, and in particular eye tension and burning sensations. (J Hum Ergol (Tokyo). 2007;36 (2):45-50). This is true for spherical or cylindrical ametropias.

[0008] The article “Binocular adaptation to near addition lenses in emmetropic adults”, by Sreenivasan V, Irving EL, Bobier WR. Vision Res. 2008;48(10): 1262-9, proposes progressive lenses designed to mitigate convergence excess, visual stress (leading to fatigue) associated with near vision, and the progression of myopia. Such lenses can control accommodation and / or accommodative vergence; however, their ability to adapt to near vision is complex for pre-presbyopic individuals, given their different active accommodation compared to presbyopic individuals. Furthermore, the use of progressive lenses designed to control the progression of myopia is also unsuitable for adults, since the kinematics of accommodative vergence are known to be completely different from those of a child or adolescent.

[0009] In the current state of the art, the design of so-called progressive contact lenses, i.e., lenses with multiple focal lengths, relies on a theoretical approach implementing wavefront models, particularly Zemike polynomials, with possible minor variations. Patents EP 2446319 B1 and EP 2762953 B1 illustrate this type of approach for contact lens design. The approach proposed in patent FR 2989179 B3 illustrates the design of contact lenses by combining the use of Zemike polynomials and evaluations based on various known transfer functions. The approach proposed in patent FR 2871247 B1 illustrates a method for compensating esophoria that exploits the accommodation-convergence relationship by relaxing the accommodation of a non-presbyopic subject. However, this approach concerns the design of a progressive spectacle lens based on the use of geometric optical models.Finally, US patent 7101042 B2 describes a design based on a pre-selected model from among linear progression, geometric progression, and logarithmic progression. Summary of the invention.

[0010] The invention aims to eliminate, or at least mitigate, all or part of the disadvantages of the prior art described above, by proposing a method for designing contact lenses which uses data from experimental measurements carried out on specific wearers and subsequently modeled by a statistical method.

[0011] To this end, a first aspect of the invention relates to a method for determining the optimized optical properties of a contact lens intended for a target subject presenting at least one ametropia other than presbyopia and heterophoria in near vision, the lens having a concave inner surface and a convex outer surface, the determination of the optimized optical properties being carried out from pa- rammeters associated with said lens, said parameters including: • at least four geometric parameters including: • a first diameter relative to the diameter of a first zone of the lens and to the internal diameter of a second zone of the lens surrounding the first zone; • a second diameter D2 relative to the external diameter of the second zone of the lens and to the internal diameter of a third zone of the lens surrounding the second zone; • a third diameter D3 relative to the external diameter of the third zone of the lens and to the internal diameter of a fourth zone of the lens surrounding the third zone; • a fourth IP diameter relative to the external diameter of the fourth zone of the lens; • at least four sets of non-optimized optical parameters obtained from measurements of phoria values ​​in near vision, on test subjects with ametropias substantially identical to those of the target subject, and from non-optimized optical parameters of contact lenses adapted to allow the target subject to achieve orthophoria; said four sets of non-optimized optical parameters comprising: • a first plurality of unoptimized optical powers pi associated with the first zone of the lens and defining a first unoptimized optical power profile; • a second plurality of non-optimized optical powers associated with the second zone of the lens and defining a second non-optimized optical power profile; • a third plurality of unoptimized optical powers ^3 associated with the third zone of the lens and defining a third unoptimized power profile; • a fourth plurality of unoptimized optical powers P4 associated with the fourth zone of the lens and defining a fourth unoptimized power profile. said process includes a calculation step, by a statistical method of symbolic regression and from the non-optimized optical parameters and the geometric parameters associated with the lens, of the power profile P^r) defining the radial evolution of the value of the optimized optical power from the center of the lens towards its outside.

[0012] Thus, the determination of the optimized optical parameters does not rely on The use of a theoretical model allows for the consideration of real-world parameters of the visual system in a specific environment. The invention thus makes it possible to design contact lenses that generate minimal effort for the wearer, particularly during prolonged use of near vision.

[0013] In addition to the characteristics just mentioned in the preceding paragraph, the process according to a first aspect of the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0014] Advantageously, the method according to a first aspect of the invention includes, before the step of calculating the optimized power profile, a step (1E1) of determining the non-optimized optical parameters from measurements of the values ​​of the phorias in near vision, on test subjects presenting ametropias substantially identical to those of the target subject, of optical parameters of contact lenses adapted to allow the target subject to be put into orthophoria.

[0015] Advantageously, during the step of determining the optical parameters, the measurements enabling the determination of optical parameters of contact lenses adapted to allow orthophoria in test subjects are carried out according to at least one of the following methods: the so-called "cover-test" method, the Berens prism bar method, the Maddox rod test method, the modified Thorington test, and any method known to those skilled in the art for measuring the convergence.

[0016] Advantageously, the value of the first diameter Di is approximately equal to 4 millimeters, the value of the second diameter D2 is approximately equal to 4.8 millimeters, the value of the third diameter D3 is between approximately 5.5 and approximately 6 millimeters and the value of the fourth diameter is approximately equal to 9 millimeters.

[0017] Advantageously, the optimized power profile of the lens P(r) is of the following form:

[0018] P}(r) when P(r) - P2( \ 1 P r) when-y <r<^ D- ^3( r) lorsque-^ <r<-~ r) lorsque™ , P <• / S ™

[0019] where 1 is the distance separating the center of the lens from the point considered, P(r) is a first optimized power profile associated with the first zone, r) is a second optimized power profile associated with the second zone, P(r) is a third optimized power profile associated with the third zone and P(r) is a fourth optimized power profile associated with the fourth zone, the optimized power profile verifying the following relationships: • max(PI(r) ) <min(P2(r) ) ; max(P3(r)) < 111111( / ^(r)); • max( / >3( r) ) < min(P4( r) ).

[0020] A second aspect of the invention relates to a contact lens intended for a target subject presenting at least one ametropia other than presbyopia and heterophoria in near vision, having a concave inner surface and a convex outer surface and presenting the following parameters: • a first zone covering a central disk having a diameter Di and a first optimized optical power profile P^r); • a second annular zone surrounding the first zone having an internal diameter D2, an external diameter D2 such that D2 > D2, and a second optimized optical power profile P2(r) such that max(P1(r)) < min(P2(r)); • a third annular zone surrounding the second zone having an internal diameter D2, a second external diameter O3 such that D3 > D2, and an optimized optical power profile P3(r) such that max(P3(r)) < min(P2(r)); • a fourth annular zone surrounding the third zone having a third internal diameter P3, a third external diameter P4 such that P4 > D3, and an optimized power profile P4(r) such that max(P3(r)) <min(P4(r)).

[0021] In addition to the characteristics just mentioned in the preceding paragraph, the lens according to a second aspect of the invention may have one or more complementary characteristics from among the following, considered individually or according to all technically possible combinations.

[0022] Advantageously, the lens according to a second aspect of the invention comprises in its composition one or more materials included in the list: silicone hydrogel materials, acrylate type materials, polyurethane type materials and alginate type materials.

[0023] Advantageously, the lens according to a second aspect of the invention comprises at least one filter adapted to filter radiation at a determined wavelength chosen from eye protection filters against radiation in the visible or near-visible range such as UV filters, UV absorbers, or blue light filters, photochromic compounds, infrared filters or visible light filters with specific absorption bands.

[0024] Advantageously, the lens according to a second aspect of the invention comprises at least one agent for modifying the tribological properties of the lens.

[0025] Advantageously, the geometric profile of the lens, according to the thickness between its concave inner surface and its convex outer surface, is spherical in the first zone, aspherical in the second zone, spherical in the third zone and aspherical in the fourth zone.

[0026] A third aspect relates to a computer program comprising instructions which, when the program is executed by a computer, lead the latter to implement the process according to a first aspect of the invention.

[0027] A fourth aspect of the invention relates to a computer-readable data carrier, on which the computer program is recorded according to a third aspect of the invention.

[0028] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0029] The figures are presented for information purposes only and in no way limit the invention.

[0030] Fig. 1 shows a flowchart of a process according to a first aspect of the invention.

[0031] Fig. 2 shows a schematic representation of a lens according to a second aspect of the invention.

[0032] Fig. 3 shows a first non-optimized power profile and a first optimized power profile using a method according to a first aspect of the invention.

[0033] Fig. 4 shows a second non-optimized power profile and a second optimized power profile using a method according to a first aspect of the invention.

[0034] Fig. 5 shows a first table presenting non-optimized optical parameters used for the implementation of a process according to a first aspect of the invention.

[0035] Figure 6 shows a second table presenting non-optimized optical parameters used for the implementation of a process according to a first aspect of the invention.

[0036] Fig. 7 shows a first table illustrating the benefits provided by a lens according to a second aspect of the invention.

[0037] Figure 8 shows a second table illustrating the benefits provided by a lens according to a second aspect of the invention.

[0038] Figure 9 shows a third table illustrating the benefits provided by a lens according to a second aspect of the invention. DETAILED DESCRIPTION

[0039] The figures are shown for illustrative purposes only and are not intended to limit the invention. Unless otherwise specified, the same element appearing in different figures has a unique reference numeral.

[0040] A first aspect of the invention illustrated in [Fig. 1] relates to a method 100 for determining an optimized optical power profile of an LE lens from parameters associated with said LE lens. The optimized optical power profile is understood to be the optical power profile obtained at the end of a calculation step 1E2 by a statistical method of the symbolic regression type.

[0041] Symbolic regression is a type of statistical method that consists of searching within a space of mathematical expressions for a model that best fits a set of data while being both as accurate (i.e., as close as possible to the actual behavior of the data) and as simple (i.e., the simplest mathematical expression with respect to accuracy) as possible. Advantageously, this type of method does not require any particular model as a starting point; the initial expressions are formed by randomly combining mathematical building blocks, and new equations are then formed by recombining the previous equations, using genetic programming.

[0042] Generally, the LE contact lens whose parameters we seek to determine has a convex outer surface and a concave inner surface. The concave inner surface has a curvature adapted to the geometry of the wearer's eye so as to be able to make contact with the surface of that eye. The outer surface is therefore the surface that is not in direct contact with the surface of the eye. The LE lens comprises a region dedicated to correction, itself composed of several optical sub-regions of spherical or aspherical shapes, with different diameters and powers. These parameters, which define these different regions of the LE lens, are called optical parameters in the jargon of those skilled in the art and in the remainder of this description.

[0043] In the context of the process 100 according to a first aspect of the invention, the parameters associated with the LE lens are of two kinds: geometric parameters mainly related to the size of the LE lens as well as the size of each Z1-Z4 zone of the lens; and non-optimized optical parameters determined from measurements carried out on patients.

[0044] More specifically, as illustrated in [Fig.2], the parameters of the LE lens include at least the following four geometric parameters: • a first diameter Dl relative to the diameter of a first zone ZI of the lens LE and to the internal diameter of a second zone Z2 of the lens LE surrounding the first zone Z2; • a second diameter ^2 relative to the external diameter of the second zone Z2 of the LE lens and the internal diameter of a third zone Z3 of the lens THE surrounding the second zone Z2; a third diameter D3 relative to the external diameter of the third zone Z3 of the LE lens and to the internal diameter of a fourth zone Z4 of the LE lens surrounding the third zone Z3; a fourth diameter D4 relative to the external diameter of the fourth zone Z4 of the LE lens.

[0045] In addition, the parameters of the LE lens include a plurality of parameters non-optimized optics comprising: a first plurality of non-optical powers optimized pj associated with the first ZI zone of the LE lens and defining a first a non-optimized power profile; a second plurality of non-optimized optical powers p-^ associated with the second zone Z2 of the LE lens and defining a second non-optimized power profile; a third plurality of non-optimized optical powers p) associated with the third zone Z3 of the LE lens and de ending a third non-optimized power profile; and a fourth plurality of non-optimized optical powers pd associated with the fourth zone Z4 of the LE lens and defining a fourth non-optimized power profile. The set formed by the first, second, third, and fourth plurality of non-optimized optical powers forms the non-optimized power profile of the LE lens. An example of a non-optimized power profile is illustrated in the form of a rhombus in [Fig. 3] and [Fig. 4]. In the example in question, for a given zone Z1-Z4, the same value is used for the set of non-optimized powers of the plurality of non-optimized powers associated with the considered zone Z1-Z4. For example, in [Fig. 3], the value of the non-optimized powers of the plurality of non-optimized powers associated with the first zone Z1 is equal to -2 diopters, while it is +8 diopters in [Fig. 4].

[0046] Generally, the non-optimized optical parameters of the LE lens are obtained from measurements of phoria values ​​in near vision, on test subjects with refractive errors substantially identical to those of the target subject, using contact lens optical parameters adapted to achieve orthophoria in the target subject. Such measurements are carried out beforehand, preferably on non-strabismic subjects with normal retinal correspondence (also called test subjects), using methods known to those skilled in the art. These may include, for example, the so-called "cover test" method, which allows for the detection of a latent deviation, the Berens prism bar method, or the Maddox rod test, which allows for the separation of each eye and thus the obtaining of maximum deviation values. Methods for measuring phorias lead to the determination of non-optimized optical parameters for all types of test subjects on which measurements are performed. The results of these measurements populate a database from which the most suitable non-optimized optical parameters for achieving orthophoria in the target subject can be determined. Non-optimized optical parameters are therefore those whose prior measurements have established that they allow for the orthophoria of one or more test subjects with a profile (i.e., refractive errors) similar or identical to that of the target subject.

[0047] In one embodiment, the method 100 further comprises, prior to step 1E2 of calculating the optimized power profile, a step 1E1 of determining the non-optimized optical parameters from measurements of phoria values ​​in near vision, on test subjects with refractive errors substantially identical to those of the target subject, and from non-optimized optical parameters of contact lenses adapted to allow the target subject to achieve orthophoria. An example of the results of a step 1E1 for determining the non-optimized optical parameters is illustrated in [Fig. 5] and [Fig. 6]. These two tables present the measurement results leading to the determination of non-optimized optical parameters that allow the various measured test subjects to achieve orthophoria.

[0048] In one embodiment, the method 100 also includes, prior to step 1E1 of determining the non-optimized optical parameters, a step 1E0 of retrieving data corresponding to the ophthalmological characteristics of the subject for whom the contact lens(es) are intended. In particular, the characteristics of the refractive error affecting the subject. Indeed, this subject, referred to as the target subject, presents at least one refractive error (myopia, hyperopia, astigmatism) other than presbyopia and a heterophoria (esophoria or exophoria) in near vision. This data is known beforehand and allows, during step 1E1 of determining the non-optimized optical parameters, the use of measurement data obtained from other subjects with comparable, i.e., substantially identical, refractive errors.

[0049] The method 100 according to a first aspect of the invention comprises a step 1E2 of calculation, by a statistical method of the symbolic regression type and from the non-optimized optical parameters and the geometric parameters associated with the LE lens, of the optimized power profile associated with each zone Z1-Z4, the set of profiles thus obtained defining the radial evolution of the value of the optimized optical power from the center of the LE lens towards its outside.

[0050] The calculation using the symbolic regression method performed in step 1E2 of determining the optimized optical power profile can be carried out, for example, using the commercial software Eureqa®. This software allows the user to select and Combine mathematical expressions from a library of 54 functions divided into 8 classes. For example, in the function library offered by the Eureqa® software, the functions used can be chosen from the "Basic" class or the "Override" class. Furthermore, learning points can be weighted or unweighted.

[0051] Furthermore, the error metric used to optimize the regression can be chosen from a library of 19 metrics. For example, from the metrics "Mean Absolute Error," "Root Square Error," "Goodness of Fit R²," "Correlation Coefficient," "Maximum Error," and "Hybrid Correlation," depending on the specific characteristics of each implementation. Finally, with equal goodness of fit (equal error metric), the model selected from among the possible models is the one with the lowest complexity index, this index being calculated by the software.

[0052] An optimized optical power profile is illustrated in [Fig. 3] and [Fig. 4] as a continuous line. More specifically, the optimized power profile of the lens P(f) is of the following form:

[0053] [Math.l] P^r) when r <-y P2(r) when y < r < -7 P3 ( r ) when-y P^r) when-^ < ry

[0054] where r is the distance separating the center of the LE lens from the point considered. Thus, the first zone ZI is associated with a first optimized power profile Pi ( r ), the second zone Z2 is associated with a second optimized power profile P2( r ), the third zone Z3 is associated with a third optimized power profile P^r) and the fourth zone Z4 is associated with a fourth optimized power profile P4( r ).

[0055] In one embodiment, the optimized power profile satisfies the following relationships: • max(PI(r) ) <min(P2(r) ) ; max(P3(r)) <min(P2(r)); • max(P3{ r) ) < min(P4( r) ).

[0056] Following a process according to a first aspect of the invention, it is possible to manufacture a LE contact lens with optimized optical parameters.

[0057] Generally, in such a LE lens, the first disc-shaped zone ZI is dedicated to distance vision. Its diameter is preferably between 0 and approximately 4 millimeters, for example, 4 millimeters. This first zone ZI has a specific optical power profile (r) adapted to correct one or more ametropias characteristic of the subject intended to wear the lens. For example, for a myopic subject, the power profile (Pr) is obtained from the first plurality of non-optimized optical parameters associated with the first zone Zl, the optical parameters of this plurality being between 0 diopters and approximately -12 diopters. For a hyperopic subject, the first plurality of non-optimized optical parameters associated with the first zone Zl can be between 0 and approximately +8 diopters. In this first zone, the geometric profile, that is, the shape of the lens according to the thickness between the concave inner surface and the convex outer surface of the lens, is spherical.

[0058] The second zone Z2 is an annular zone having an internal diameter D[ and an external diameter D2 greater than . This zone Z2 is dedicated to intermediate vision. For example, for a myopic subject, the power profile P2( r) is obtained from the second plurality of non-optimized optical parameters, which can range from 1 diopter to approximately -11 diopters. For a hyperopic subject, the second plurality of non-optimized optical parameters can range from +1 to approximately +9 diopters. Furthermore, this second zone Z2 aims to correct the spherical aberration related to the first zone Z1 and therefore has an aspheric geometric profile. Those skilled in the art will appreciate that in another embodiment, the LE lens can have a spherical geometric profile in the second zone Z2.

[0059] The third zone Z3 is an annular zone with an internal diameter D2 and an external diameter μ greater than the internal diameter D2. For example, the external diameter of the third zone is between approximately 5.5 and approximately 6 millimeters. The third zone Z3 also has a spherical geometric profile. Those skilled in the art will appreciate that in another embodiment, the lens may have an aspheric geometric profile in the third zone Z3.

[0060] Finally, the fourth zone Z4 is an annular zone with an internal diameter D3 and an external diameter D4 which determines the total diameter of the correction zone of the LE lens. The diameter D4 is, for example, equal to 9 millimeters.

[0061] Thus, a second aspect of the invention relates to a LE contact lens that can be obtained using a method 100 according to a first aspect of the invention. More particularly, a second aspect of the invention relates to a LE contact lens intended for a target subject presenting at least one ametropia other than presbyopia and heterophoria in near vision, having a concave inner surface and a convex outer surface and having the parameters, known as pa- optical rammeters, as follows: • a first ZI zone covering a central disk having an optimized diameter and first optical power profile; • a second annular zone Z2 surrounding the first zone having an internal diameter and an external diameter D2 such that D2 > Dy and a second optimized optical power profile P2(r) such that max((r)) < min(P2(r)); • a third annular zone Z3 surrounding the second zone having an internal diameter D2, a second external diameter O3 such that D3 > D2 and an optimized optical power profile P3(r) such that max(P3(r)) < min(P2(r)); • a fourth annular zone Z4 surrounding the third zone having a third internal diameter D3, a third external diameter such that > D3 and an optimized power profile P4( r) such that max(P3(r) ) <min(p4(r) ).

[0062] In one embodiment, the LE lens according to a second aspect of the invention comprises in its composition one or more materials included in the list: silicone hydrogel materials, acrylate-type materials, polyurethane-type materials and alginate-type materials.

[0063] In one embodiment, the LE lens according to a second aspect of the invention comprises at least one filter adapted to filter radiation at a determined wavelength chosen from eye protection filters against radiation in the visible or near-visible range such as UV filters, UV absorbers, or blue light filters, photochromic compounds, infrared filters or visible light filters with specific absorption bands.

[0064] In one embodiment, the LE lens according to a second aspect of the invention comprises at least one agent for modifying the tribological properties of the lens.

[0065] In one embodiment, the geometric profile of the LE lens along the thickness between its concave inner surface and its convex outer surface is spherical in the first zone Z1, aspherical in the second zone Z2, spherical in the third zone Z3 and aspherical in the fourth zone Z4.

[0066] It has been observed that LE lenses according to a second aspect of the invention, i.e., lenses capable of being manufactured by a process according to a first aspect of the invention, limit visual fatigue in wearers. More specifically, in a comparative test with contact lens wearers, it was observed that the LE lens thus obtained significantly improved phoria and comfort, without any deterioration in visual acuity compared to the lenses worn previously. The measurement of phorias uses the Maddox rod test. Heterophorias that can The phoria values ​​vary depending on the visual activity prior to the measurement (near vision / distance vision ratio). Therefore, the recording time for phoria values ​​must be identical for all measurements or correspond to an "equal" level of visual activity before the test.

[0067] More specifically, during the study, phoria measurements were taken simultaneously with comfort measurements after 6 hours of wear. The results of this study are presented in [Fig. 7], [Fig. 8], and [Fig. 9], as well as the conditions under which it was carried out. The study presented in these three figures is an open-label, non-randomized study conducted with a cohort of approximately twenty subjects. The subjects serve as their own controls: clinical criteria are evaluated on a "before versus after" basis (currently worn lens versus the lens of the invention). There is no washout between the two devices. The LE lens according to a second aspect of the invention is adapted and tested in patients with the following characteristics: • myopia up to -6 diopters; • hyperopic up to +4 diopters; • astigmatism up to 0.50 diopters (i.e., absence of cylinder or negligible cylinder, so that there is no loss of visual acuity with equivalent spherical correction); • Patients of both sexes aged 18 to 40 years who are not presbyopic.

[0068] However, the following patients are excluded from this study: • with presbyopia that is corrected or requires correction for presbyopia; • wearing extended wear soft lenses (day and night lenses); • equipped with glasses and / or wearing rigid contact lenses (RGP lenses), scleral lenses, orthokeratological lenses or hybrid contact lenses.

[0069] The data from this study were analyzed using Addinsoft's XLSTAT software. The normality of the data distribution was tested using the Shapiro-Wilk and Lilliefors tests. Comparisons were therefore performed using the test adapted for two comparisons (no assumption was made about the direction of variation of the variables). The significance level (alpha risk) was set at 5%.

[0070] Phoria values ​​are increased in a statistically significant manner in the group corresponding to the lenses of the invention. Similarly, near vision comfort is increased in a statistically significant manner in the group wearing the lenses of the invention compared to non-inventory lenses usually worn by the subjects. Visual acuity is identical (no statistically significant difference) to that of the lenses usually worn. The invention therefore leads to an improvement in phoria and wearing comfort, without deterioration of visual acuity compared to commercially available lenses of the prior art.

Claims

Claims

1. Method (100) for determining the optimized optical properties of a contact lens (LE) intended for a target subject having at least one ametropia different from presbyopia and heterophoria in near vision, the lens (LE) having a concave internal surface and a convex external surface, the determination of the optimized optical properties being done from a parameter associated with said lens (LE), said parameters comprising: at least four geometric parameters including: • a first diameter relative to the diameter of a first zone (Z1) of the lens (LE) and to the internal diameter of a second zone (Z2) of the lens (LE) surrounding the first zone (Z2); • a second diameter D2 relative to the external diameter of the second zone (Z2) of the lens (LE) and to the internal diameter of a third zone (Z3) of the lens (LE) surrounding the second zone (Z2); • a third diameter D3 relative to the external diameter of the third zone (Z3) of the lens (LE) and to the internal diameter of a fourth zone (Z3) of the lens (LE) surrounding the third zone (Z3); • a fourth diameter D4 relative to the external diameter of the fourth zone (Z4) of the lens (LE); at least four series of non-optimized optical parameters obtained from measurements of the values ​​of phorias in near vision, on test subjects having ametropias substantially identical to those of the target subject, of optical parameters of contact lenses adapted to allow the target subject to be put into orthophoria; said four series of non-optimized optical parameters comprising: • a first plurality of non-optimized optical powers p) associated with the first zone (Zl) of the lens (LE) and defining a first non-optimized optical power profile; a second plurality of non-optimized optical powers jd associated with the second zone (Z2) of the lens (LE) and defining a second non-optimized optical power profile; • a third plurality of non-optimized optical powers P3 associated with the third zone (Z3) of the lens (LE) and defining a third non-optimized power profile; • a fourth plurality of non-optimized optical powers P4 associated with the fourth zone (Z4) of the lens (LE) and defining a fourth non-optimized power profile; said method (100) comprising a step of calculating, by a statistical method of symbolic regression type and from the non-optimized optical parameters and the geometric parameters associated with the lens (LE), the power profile P(r) defining the radial evolution of the value of the optimized optical power from the center of the lens (LE) towards its exterior.

2. Method (100) according to the preceding claim further comprising, before the step (1E2) of calculating the optimized power profile, a step (1E1) of determining the non-optimized optical parameters from measurements of the values ​​of the phorias in near vision, on test subjects having ametropias substantially identical to those of the target subject, of optical parameters of contact lenses adapted to allow the target subject to be put into orthophoria.

3. Method according to the preceding claim, characterized in that during step (1E1) of determining the optical parameters, the measurements allowing the determination of optical parameters of contact lenses suitable for allowing the orthophoria of test subjects are carried out according to at least one of the following methods: the so-called "cover test" method, the Berens prism bar method, the Maddox rod test method, the modified Thorington test and any method known to those skilled in the art for measuring convergence.

4. Method according to one of the preceding claims, in which the value of the first diameter Di is substantially equal to 4 millimeters, the value of the second diameter D2 is substantially equal to 4.8 millimeters, the value of the third diameter D3 is between approximately 5.5 and about 6 millimeters and the value of the fourth diameter is approximately equal to 9 millimeters.

5. Method according to one of the preceding claims, characterized in that the optimized power profile of the lens P(r) is of the following form: P^r) when r P9( r) when V < r < -y P ('7= DD P3(r) when-^- <r<-f P4(r) when y < r < y where r is the distance separating the center of the lens from the point considered, ( r ) is the first optimized power profile associated with the first zone, P2(r) is the second optimized power profile associated with the second zone, P3 ( r ) is the third optimized power profile associated with the third zone and P^(r) is the fourth optimized power profile associated with the fourth zone, the optimized power profile verifying the following relations: max(P1(r) ) < min(P2(r) ) max(P3(r) ) <min(P2(r) ) max(P3(r) ) £min(P4(r) )

6. Contact lens (LE) intended for a target subject having at least one ametropia different from presbyopia and heterophoria in near vision, having a concave internal surface and a convex external surface and having the following parameters, called optical parameters: - a first zone (Zl) covering a central disk having a diameter and a first optimized optical power profile P^r); - a second annular zone (Z2) surrounding the first zone having an internal diameter 29j, an external diameter D2 such that > ​​^t and a second optimized optical power profile P2(r) such that max(Pj(r)) <min(P2(r) ) ; - a third annular zone (Z3) surrounding the second zone having an internal diameter D2, a second external diameter D3 such that D3 > PL and an optimized optical power profile P3( r ) such that max( P3( r ) ) < min (P2( r ) ); - a fourth annular zone (Z4) surrounding the third zone having a third internal diameter, a third external diameter D4 such that D4 > D3 and an optimized optical power profile P4 ( r ) such that max ( P3 ( r ) ) < min ( P4 ( r ) ) the geometric profile of the lens (LE) according to the thickness between its concave internal surface and its convex external surface being spherical in the first zone (Z1), aspherical in the second zone (Z2), spherical in the third zone (Z3) and aspherical in the fourth zone (Z4).

7. Lens (LE) according to the preceding claim comprising in its composition one or more materials included in the list: silicone hydrogel materials, acrylate-type materials, polyurethane-type materials and alginate-type materials.

8. Lens (LE) according to one of the two preceding claims comprising at least one filter adapted to filter radiation at a determined wavelength chosen from filters for protecting the eye against radiation in the visible or near-visible range such as UV filters, UV absorbers, or blue light filters, photochromic compounds, infrared filters or visible light filters with specific absorption bands.

9. Lens (LE) according to one of the three preceding claims comprising at least one agent for modifying the tribo-logical properties of the lens.

10. A computer program comprising instructions which, when the program is executed by a computer, cause the latter to implement the method according to one of claims 1 to 5.

11. Computer-readable data carrier, on which the computer program according to claim 10 is recorded.

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