Method for determining an ophthalmic lens intended to be worn by a non-esophoria individual

Abstract

The invention concerns a method implemented by computer means for determining an ophthalmic lens intended to be worn by a non-esophoria individual, said ophthalmic lens being adapted to provide to the individual a vision correction at at least two different distances, said vision correction being based on wearer data including prescription data of the individual. The method comprises the following steps: receiving binocular visual parameters of the individual; calculating an addition value for the individual based on their binocular visual parameters; defining said ophthalmic lens based on said wearer data and on the calculated addition value.

Description

[0001] Method for determining an ophthalmic lens intended to be worn by a non- esophoria individual

[0002] TECHNICAL FIELD

[0003] The disclosure relates to a method, for example, implemented by computer means for determining and providing an ophthalmic lens intended to be worn by a non- esophoria individual.

[0004] The disclosure also relates to an associated device for implementing the method according to the disclosure,

[0005] The disclosure further relates to an associated computer program product able to be implemented by the device according to the disclosure.

[0006] BACKGROUND OF THE DISCLOSURE

[0007] Presbyopia is a physiological insufficiency of accommodation associated with the aging of the eye that results in progressively worsening ability to focus clearly on close objects. Presbyopia appears generally from the age of 40-45 and stabilizes around the age of 60.

[0008] Before presbyopia, some people may need a power addition at near vision for more comfortable vision. However, there is no known methodology to personalize the determination of this addition value regarding binocular vision though it is known that binocular vision plays an important role.

[0009] Different methods exist to assess the need of addition. For this, Eye Care Professionals (ECP) use Jackson Cross Cylinder, Red / Green balance, Balance between positive and negative relative accommodations, Link between age and addition value and / or the formula:

[0010] Add=2.5-0.5*Amax

[0011] Where Add represents the addition value and Amax the maximum accommodation value.

[0012] However, these methodologies apply only after 40yo for presbyopes. Currently, on the market, anti-fatigue lenses are age dependent only.

[0013] However, deciding on an addition, for a pre-presbyopes, only with age may not be the most relevant, whereas binocular and accommodative capacity are more significant. Not considering these physiological parameters can lead to the following symptoms: asthenopia, headaches, double vision. This would be due to binocular vision being overused by inappropriate addition values (e.g. exophoria worsens when an addition is worn).

[0014] Without those important parameters, choosing the correct addition value may be difficult.

[0015] Indeed, among the targeted population, some should wear antifatigue with addition power and others will not be comfortable with it.

[0016] In this context, there is a need for a methodology to better determine the prescription for pre-presbyopes as well as for the provision of more suitable ophthalmic lens. This need exists for pre-presbyopes of course, but it can also be relevant for presbyopes.

[0017] An aim of the present disclosure is to propose a method and an associated device that solve all or part of the above-mentioned problems.

[0018] The above technical problems are solved by the determination of the addition value from physiological characteristics including binocular visual parameters.

[0019] The present disclosure proposes a method using, instead of the age, physiological parameters based on binocular and accommodative capacity.

[0020] Advantageously, the measurement of binocular visual parameters permits to determine a proper addition value and therefore the provision of an appropriate ophthalmic lens based on the determined addition value.

[0021] SUMMARY OF THE DISCLOSURE

[0022] To this end, the disclosure proposes a method, for example implemented by computer means, for determining an ophthalmic lens intended to be worn by a non- esophoria individual, said ophthalmic lens being adapted to provide to the individual a vision correction at at least two different distances, said vision correction being based on wearer data including prescription data of the individual, the method comprising the following steps: receiving binocular visual parameters of the individual; calculating an addition value for the individual based on their binocular visual parameters; defining said ophthalmic lens based on said wearer data and on the calculated addition value.

[0023] According to further embodiments which can be considered alone or in combination:

[0024] - the method further comprises a step of measuring binocular visual parameters of the individual; and / or

[0025] - the step of definition of said ophthalmic lens further comprises selecting an ophthalmic lens among a plurality of predetermined ophthalmic lenses based on the calculated addition value; and / or

[0026] - the ophthalmic lens is chosen among spectacle lens, active spectacle lens with variable optical power, contact lens or active contact lens; and / or

[0027] - the binocular visual parameters comprise at least one of, near phoria and positive fusional reserve; and / or

[0028] - the lens is designed for an individual fulfilling at least Sheard criterion and / or the following criterion:

[0029] Where “near phoria” represents near phoria measurement, “near phoria+d” represents near phoria measurement with an addition of a predetermined number of diopters comprised between 0.50D and 2.00D, “Positive fusional reserve” represents the maximum capacity of convergence; and / or

[0030] - at least one of the binocular visual parameters, called “binocular accommodation parameter” is also related to accommodation and wherein the formula to determine addition value contains a term related to binocular vision and a term also related to accommodation; and / or - the formula to determine addition value is:

[0031] / Near phoria+d— Near phoria \

[0032] 1 — - - - - : - - - : - * k * binocular accommodation parameter

[0033] \ Postive tusional reserve — Near phona+d /

[0034] Where k represents a constant value comprised between 1 / 3 and 2 / 3, and preferentially, equal to 1 / 2;

[0035] - the binocular accommodation parameter and the near phoria are measured at a distance lower than 1 meter, preferentially at a distance of 40 cm; and / or

[0036] - the binocular accommodation parameter of the individual corresponds to its accommodation capacity; and / or

[0037] - the binocular accommodation parameter is the maximum binocular tolerated addition; and / or

[0038] - depending on whether the addition value is lower or higher than a predefined threshold value, the ophthalmic lens is a first type of lens or a second type of lens , wherein:

[0039] - said first type of lens being an ophthalmic lens having a complex surface with a substantially umbilic meridian and a mean-sphere progression value as said addition value and which vision correction is provided at a primary vision gaze direction,

[0040] - said second type of lens being a single vision ophthalmic lens having at least a prescribed optical power, providing to the wearer in standard wearing condition in at least a first gazing direction, the prescribed optical power when gazing at a first distance and in at least a second gazing direction the prescribed optical power when gazing at a second distance, the first and second distance being different and the first and second gazing direction being different,

[0041] - said threshold value being comprised between 0,2 and 0,6; and / or

[0042] - the method further comprising, providing visual trainings and / or ergonomics advices.

[0043] The disclosure also relates to an associated device for determining an ophthalmic lens intended to be worn by a non-esophoria individual, said ophthalmic lens being adapted to provide to the individual a vision correction at at least two different distances, said vision correction being based on wearer data including prescription data of the individual. The device is configurated to implement the method according to the disclosure and comprises at least one human machine interface, at least one memory and at least one processor, wherein:

[0044] - the at least one human machine interface is configured to receive at least binocular visual parameters value of the individual;

[0045] - the at least one memory is configured to at least store binocular visual parameters;

[0046] - the at least one processor is programmed to:

[0047] - calculate an addition value for the individual based on their binocular visual parameters, and

[0048] - define said ophthalmic lens based on said wearer data and on the calculated addition value.

[0049] The disclosure further relates to a computer program product able to be implemented by the device according to the disclosure. The computer program product comprises one or more stored sequence of instructions that is accessible to a processor and which, when executed by the processor, causes the processor to carry out the steps of the method according to the disclosure.

[0050] The disclosure also relates to a computer-readable storage medium having a program recorded thereon; where the program makes the computer execute the method of the disclosure.

[0051] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing”, “computing”, “calculating”, or the like, refer to the action and / or processes of a computer or computing system, or similar electronic computing device, that manipulates and / or transforms data represented as physical, such as electronic, quantities within the computing system's registers and / or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices. Embodiments of the present disclosure may include apparatuses for performing the operations herein. This apparatus may be specially constructed for the desired purposes, or it may comprise a general purpose computer or Digital Signal Processor ("DSP") selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs) electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, SIM cards, or any other type of media suitable for storing electronic instructions, and capable of being coupled to a computer system bus.

[0052] The methods presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below.

[0053] In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the disclosure as described herein.

[0054] BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Non-limiting embodiments of the disclosure will now be described with reference to the accompanying drawing wherein: o figure l is a flowchart of an example of implementation of the method according to the disclosure; and o figure 2 is a flowchart of a particular implementation of the method according to the disclosure.

[0056] Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve the understanding of the embodiments of the present disclosure.

[0057] DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE

[0058] The disclosure relates to a method to prescribe, or to have a better prescription, for personalized near vision solution considering the physiological parameters of the individual.

[0059] This method is aimed to pre-presbyope people, so non presbyope individuals, and presbyope people. Pre-presbyope people can be, for example, people of 36 to 43 years old.

[0060] More precisely, the disclosure relates to a method for determining an ophthalmic lens intended to be worn by a non-esophoria individual. The method also allow to manufacture the determined ophthalmic lens and thus the provision of the determined ophthalmic lens. The method is therefore intended for exophoria or orthophoria persons.

[0061] Throughout of the description, the utilization of the term “ophthalmic lens” refers to a spectacle lens, an active spectacle lens with variable optical power, a contact lens or an active contact lens or any other type of equivalent lens.

[0062] Likewise, in the context of the present disclosure, the term “determining an ophthalmic lens” refers to the action of defining an ophthalmic lens and also the action of selecting a lens among a plurality of existing or predetermined ophthalmic lenses. The selection of the lens can be based on a visual parameter as addition value.

[0063] According to the disclosure, the ophthalmic lens is adapted to provide to the individual a vision correction at at least two different distances. The vision correction is based on wearer data including prescription data of the individual.

[0064] The “prescription” is a set of optical characteristics of optical power, of astigmatism and, where relevant, of addition. The prescription is determined by an ophthalmologist in order to correct the vision defects of an individual, for example by means of a lens positioned in front of his eye. Generally speaking, the prescription for a progressive addition lens comprises values of optical power and of astigmatism at the distance-vision point and, where appropriate, an addition value. The method could be, for example, implemented by computer means.

[0065] As illustrated on figure 1, the method according to the disclosure comprises at least:

[0066] - receiving Stpl 1 binocular visual parameters of the individual;

[0067] - calculating Stpl 2 an addition value for the individual based on their binocular visual parameters;

[0068] - defining Stpl 3 said ophthalmic lens based on said wearer data and on the calculated addition value.

[0069] According to an implementation mode, after the definition step Stpl 3, the method also comprises a step of manufacturing the defined ophthalmic lens. Therefore, the method allow to provide the ophthalmic lens intended to be worn by the individual

[0070] In the sense of the invention, “binocular visual parameters” correspond to any measurable physiological parameters of how the two eyes work together to create a single, cohesive visual perception.

[0071] For both contact lens and spectacle lens (including active lens), the term “addition value" refers to the power difference when the wearer is looking at two different distances.

[0072] The method, and more particularly the lens design, is aimed to individual which fulfills at least Sheard criterion and / or the following second criterion:

[0073] Where “near phoria” represents near phoria measurement, “near phoria+d” represents near phoria measurement with an addition of a predetermined number d of diopters, said number being comprised between 0.50D and 2.00D,

[0074] “Positive fusional reserve” represents the maximum capacity of convergence,

[0075] According to an implementation mode, the near phoria is measured at a distance lower than 1 meter and preferentially at a distance of 40 cm.

[0076] The method can be used by different people for different purposes. The method can be used to order ophthalmic lens, for example, in order to make complementary recommendation. It can also be used by eye care professionals, as a preparative method, for example, to make recommendations to their clients.

[0077] According to an implementation mode, the parameters received during the receiving step Stpl 1 may have been measured beforehand and provided, for example to a manufacturer.

[0078] In certain mode of implementation, for example when the method is directed to an eye care professional, prior to the receiving step Stpl 1, the method further comprises a step StplO of measuring the binocular visual parameters of the individual.

[0079] During this step StplO of measurement of the binocular visual parameters, the individual should keep both eyes open. The measurement is preferably done for both eye at the same time. The measurement result can then be used for both eyes.

[0080] The binocular parameters received during the step Stpl 1, comprise at least one of, near phoria and positive fusional reserve.

[0081] Among the list of binocular parameters, at least one of them is also related to accommodation. For the rest of the description, this at least one parameter will be called “binocular accommodation parameter”.

[0082] In the sense of the invention, the term “binocular accommodation parameter” corresponds to any measurable physiological parameters that reflect an accommodative behavior, done binocularly that is when both eyes are looking at the same single object.

[0083] During a step Stpl2, an addition value is calculated for the individual. The calculation is based on their binocular visual parameters.

[0084] According to the disclosure, the formula to determine this addition value contains a term related to binocular vision and a term also related to accommodation. More precisely, the addition value is determined with the following formula:

[0085] / Near phoria+d— Near phoria \

[0086] 1 — - - - - : - - - : - * k * binocular accommodation parameter

[0087] \ Postive tusional reserve — Near phona+d /

[0088] In this formula,

[0089] “near phoria” represents near phoria value of the individual; “near phoria+d” represents near phoria value with an addition of a predetermined number d of dioptric wherein, d is a number comprised between

[0090] 0.50D and 2.00D;

[0091] “Positive fusional reserve” represents the maximum capacity of convergence of the individual;

[0092] “k” is a constant value comprised between 1 / 3 and 2 / 3 and preferentially, equal to 1 / 2;

[0093] “binocular accommodation parameter” represents the value of the binocular accommodation parameter.

[0094] According to an implementation mode, the binocular accommodation parameter and the near phoria are measured at a distance lower than 1 meter and preferentially at a distance of 40 cm.

[0095] According to an implementation mode, the binocular accommodation parameter of the individual corresponds to its accommodation capacity.

[0096] According to a preferred implementation mode, the binocular accommodation parameter is the maximum binocular tolerated addition of the individual.

[0097] After the calculation Stpl2 of the addition value, this calculated value is compared to a predefined threshold value.

[0098] According to an implementation mode, the threshold value is comprised between 0,2 and 0,6.

[0099] If the calculated addition value is higher than or equal a predefined threshold value, for example 0.4, then the ophthalmic lens is of a first type of lens. This first type of lens is an ophthalmic lens having a complex surface with a substantially umbilic meridian and a mean-sphere progression value as said addition value. The vision correction is provided at a primary vision gaze direction.

[0100] Such an ophthalmic lens may have a complex rear surface such as, for example, the lenses described in the US patent US 7,540,610 B2.

[0101] The complex rear surface of those lenses has a substantially umbilic meridian and a mean-sphere progression, referred to as an addition value. The meridian of the complex surface is a line formed by the intersection points with the complex surface of mean gaze directions of a wearer when he is looking from far to near vision. The mean-sphere progression is defined as the difference between the two reference points namely, the centering point and the given reference point. On the contrary, if the calculated addition value is lower than the predefined threshold value, for example 0.4, then the ophthalmic lens is of a second type of lens. This type of lens is a single vision ophthalmic lens.

[0102] This ophthalmic lens may have at least a prescribed optical power, providing to the wearer in standard wearing condition in at least a first gazing direction, the prescribed optical power when gazing at a first distance and in at least a second gazing direction the prescribed optical power when gazing at a second distance, the first and second distance being different and the first and second gazing direction being different,

[0103] This type of ophthalmic lens may be, for example, of the lens described in the European patent application EP 3547013 Al.

[0104] According to an implementation mode, during the definition of the lens, the calculated addition value is rounded to its nearest value before its implementation in the lens design.

[0105] According to an implementation example, the calculated value is rounded to the nearest tenth. For example, if the calculated addition value is egal to 0.58D, the implemented addition value will be 0.6D. Likewise, if the result of the calculation is 0.33D, the implemented addition value in the lens design will be 0.3D.

[0106] An other mode of implementation corresponds to the case where the lens is selected among a plurality of existing or predetermined ophthalmic lenses. In this case, the selected lens will be the one whose addition value is the closest to the calculated addition value.

[0107] According to an implementation mode, visual trainings and / or ergonomics advices can, also be provided to the individual.

[0108] A particular mode of implementation of the disclosure is depicted on figure 2.

[0109] During a step Stp21, a near phoria measurement is perform. This permits to determine if the individual is an exophoria, an orthophoria or an esophoria person.

[0110] At the end of the measurement, if the individual is an exophoria person or an orthophoria person in Stp 22, a near positive fusional reserve measurement Stp23 is performed. Then if the binocular visual parameters of the individual fulfill the Sheard criterion in Stp 24, an accommodative rock is performed in Stp 25.

[0111] Sheard criterion mentions that the fusional reserve, that is opposite to the phoria, should be at least twice larger than said phoria in order to maintain a comfortable vision.

[0112] At the end of this test, four cases can occur.

[0113] The result can be “block +” Stp 261, “block Stp 263, none of “block +” or “block Stp 262 , or “block+ and Stp264.

[0114] The notations “block +”, “block “none of block + or block or “block+ and represent results of the rock test as used, for example, in JJ Saladin, Phorometry and stereopsis. In: Borish’s Clinical Refraction (Benjamin WJ, editor, W.B Saunders: Philadelphia, PA. 1998, Ch 20, pp 726-773).

[0115] For example, when adding + or - 2D lenses in front of the eyes, the individual might be blocking on the + lenses (i.e. block +) or on the - lens (i.e. block -) if their accommodation system cannot bear such change over time.

[0116] Then, the formula to determine the addition value described above is performed by Stp 28.

[0117] In the particular case of the “block +” result, visual training and / or ergonomics advices can further be provided in Stp 271 to the individual.

[0118] In the event that the test result is “block+ and then the formula described in the present disclosure can not be applied. The individual should refer to an ophthalmologist and / or an optometrist in Stp 274.

[0119] At the end of the calculation step Stp 28, the calculated additional value is compared in Stp 291 and Stp 292 to a threshold value T.

[0120] In Stp 291, if the additional value is greater than or egal to the threshold value, then the ophthalmic lens is of the first type.

[0121] In Stp 292, if the additional value is lower than the threshold value, then the ophthalmic lens is of the second type.

[0122] In this table, A represents prismatic diopter. One prismatic diopter corresponds to a deviation of 1cm at Im.

[0123] The table above presents some examples of results obtained with the method described above.

[0124] For the examples below, we will assume that the threshold value which determine the type of lens is equal to 0.4D.

[0125] If we consider the fifth column, the measurements indicate a near phoria value equal to 3.5 A, a near phoria+i value equal to 10 A, a positive fusional reserve equal to 25 A and a maximum tolerated addition value equal to 1.5 D.

[0126] After calculation, the addition value is equal to 0.425 D. This calculated addition value is higher than the threshold so the lens will be of the first type.

[0127] In a first implementation mode, this value is directly implemented in the lens design.

[0128] According to a second implementation mode, this value is rounded to 0.4D before its implementation in the lens design.

[0129] If we consider the case where the lens is chosen among existing or predefined ophthalmic lenses with additional values, for examples as 0.2D, 0.4D and 0.6D, the existing lens with the closest additional value will be a lens with an addition value equal to 0.4D.

[0130] If we consider now the fourth column, the measurements indicate a near phoria value equal to 4 A, a near phoria+i value equal to 8 A, a positive fusional reserve equal to 17 A and a maximum tolerated addition value equal to 1 D.

[0131] After calculation, the addition value is now equal to 0.278 D. This calculated addition value is lower than the threshold so the lens will be of the second type. In a first implementation mode, this value is directly implemented in the lens design.

[0132] According to a second implementation mode, the addition value is rounded to 0.2 D before its implementation in the lens design.

[0133] If we consider the case where the lens is chosen among existing or predefined ophthalmic lenses with additional values as 0.2D,0.4D and 0.6D, the existing lens with the closest additional value will be a lens with an addition value equal to 0.2D.

[0134] In a different way, taking into account the visual parameters of the individual makes it possible to obtain different addition values. Therefore, the method according to the disclosure allows to better determine the addition value adapted to the individual. Advantageously, each individual will be prescribed a type of lens with an addition value that is really adapted to their vision and their needs.

[0135] An other object of the disclosure is a device for determining an ophthalmic lens intended to be worn by a non-esophoria individual. This device is configured to implement the method, according to the disclosure, described above.

[0136] According to an embodiment, the device comprises at least one human machine interface, at least one memory and at least one processor.

[0137] The at least one human machine interface is configured to receive at least the binocular visual parameters value of the individual.

[0138] According to an embodiment, the human machine interface is also configured to transfer the received parameters in a memory.

[0139] The at least one memory is configured to at least store the binocular visual parameters of the individual.

[0140] According to an embodiment, the memory is also configured to store the formula to calculate the addition value.

[0141] According to an embodiment, the memory is configured to store the Sheard criterion and / or the second criterion defined above.

[0142] The at least one processor is programmed to read data stored in a memory and to perform different calculation from these data. The processor is programmed at least to calculate the addition value for the individual based on their binocular visual parameters. It is also programmed to define the ophthalmic lens based on the wearer data and on the calculated addition value.

[0143] The processor is programmed to test different criterion. The processor is programmed to test if the addition value is higher or lower than the threshold value. It is also programed to test if the binocular visual parameters of the individual fulfill the Sheard criterion and / or the second criterion.

[0144] The disclosure also relates to a computer program product able to be implemented by the device according to the disclosure and more particularly by at least one of its processors. The computer program product comprises one or more stored sequence of instructions that is accessible to at least one processor and which, when executed by said processor, causes the processor to carry out the steps of the method according to the disclosure.

[0145] The one or more sequences of instructions comprises at least the binocular visual parameters of the individual and the formula to determine the addition value. The processor executes the sequences of instructions so as to calculate said addition value.

[0146] The processor executes also the sequences of instructions so as to test different criterion. The processor is able to test if the addition value is higher or lower than the threshold value. It is, for example, also able to test if the binocular visual parameters of the individual fulfill the Sheard criterion and / or the second criterion.

[0147] An other object of the disclosure is a computer-readable storage medium having a program recorded thereon; where the program makes the computer execute the method of the disclosure.

[0148] Many further modifications and variations will be apparent to those skilled in the art upon making reference to the foregoing illustrative embodiments, which are given by way of example only and which are not intended to limit the scope of the disclosure, that being determined solely by the appended claims.

[0149] In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be advantageously used. Any reference signs in the claims should not be construed as limiting the scope of the disclosure.

Claims

CLAIMS1. Method implemented by computer means for determining an ophthalmic lens intended to be worn by a non-esophoria individual, said ophthalmic lens being adapted to provide to the individual a vision correction at at least two different distances, said vision correction being based on wearer data including prescription data of the individual, the method comprising the following steps:- receiving binocular visual parameters of the individual;- calculating an addition value for the individual based on their binocular visual parameters;- defining said ophthalmic lens based on said wearer data and on the calculated addition value.

2. Method according to claim 1 further comprising a step of measuring binocular visual parameters of the individual.

3. Method according to claim 1 or 2 wherein the step of definition of said ophthalmic lens further comprises selecting an ophthalmic lens among a plurality of predetermined ophthalmic lenses based on the calculated addition value.

4. Method according to any of the preceding claims wherein said ophthalmic lens are chosen among spectacle lens, active spectacle lens with variable optical power, contact lens or active contact lens.

5. Method according to any of the preceding claims wherein the binocular visual parameters comprise at least one of, near phoria and positive fusional reserve.

6. Method according to any of the preceding claims wherein the ophthalmic lens is design for an individual fulfilling at least Sheard criterion and / or the following criterion:Where “near phoria” represents near phoria measurement,“near phoria+d” represents near phoria measurement with an addition of a predetermined number of diopters comprised between 0.50D and 2.00D, “Positive fusional reserve” represents the maximum capacity of convergence,7. Method according to any of the preceding claims wherein at least one of the binocular visual parameters, called “binocular accommodation parameter” is also related to accommodation and wherein the formula to determine addition value contains a term related to binocular vision and a term also related to accommodation.

8. Method according to any one of claims 1 to 7 wherein the formula to determine addition value is: / Near phoria+d— Near phoria \| _ _ I *\ Postive fusional reserve — Near phoria+d / * binocular accommodation parameterWhere k represents a constant value comprised between 1 / 3 and 2 / 39. Method according to the preceding claim wherein the binocular accommodation parameter and the near phoria are measured at a distance lower than 1 meter, preferentially at a distance of 40 cm.

10. Method according to any one of claims 7 to 9 wherein the binocular accommodation parameter of the individual corresponds to its accommodation capacity.

11. Method according to any one of claims 7 to 10 wherein the binocular accommodation parameter is the maximum binocular tolerated addition.

12. Method according to any one of the preceding claims wherein, depending on whether the addition value is lower or higher than a predefined threshold value, the ophthalmic lens is a first type of lens or a second type of lens, wherein:- said first type of lens being an ophthalmic lens having a complex surface with a substantially umbilic meridian and a mean-sphere progression value as saidaddition value and which vision correction is provided at a primary vision gaze direction,- said second type of lens being a single vision ophthalmic lens having at least a prescribed optical power, providing to the wearer in standard wearing condition in at least a first gazing direction, the prescribed optical power when gazing at a first distance and in at least a second gazing direction the prescribed optical power when gazing at a second distance, the first and second distance being different and the first and second gazing direction being different,- said threshold value being comprised between 0,2 and 0,6.

13. Method according to any one of the preceding claims further comprising, providing visual trainings and / or ergonomics advices.

14. Device for determining an ophthalmic lens intended to be worn by a non- esophoria individual, said ophthalmic lens being adapted to provide to the individual a vision correction at at least two different distances, said vision correction being based on wearer data including prescription data of the individual said device being configurated to implement the method according to any one of the preceding claims, the device comprising at least one human machine interface, at least one memory and at least one processor, wherein:- the at least one human machine interface is configured to receive at least binocular visual parameters value of the individual;- the at least one memory is configured to at least store binocular visual parameters;- the at least one processor is programmed to:- calculate an addition value for the individual based on their binocular visual parameters, and- define said ophthalmic lens based on said wearer data and on the calculated addition value.

15. Computer program product able to be implemented by the device according to the preceding claim, comprising one or more stored sequence of instructions that isaccessible to a processor and which, when executed by the processor, causes the processor to carry out the steps of the method according to any of claims 1 to 13.

Images