Lens systems for controlling anisometropia and methods for controlling anisometropia

Abstract

This invention relates to a myopia control lens configured to control anisometropia in a patient with at least one myopic eye or a pre-myopic eye. More specifically, this invention relates to at least one ocular lens for use in eyeglasses or contact lenses configured to control and / or treat (prevent and minimize) anisometropia. The ocular lens of this invention can be used in any anisometropia condition where at least one eye in the eye is myopic or in the pre-myopic stage, regardless of whether the refraction and refraction are spherical and / or astigmatic.

Description

Technical Field

[0001] The present invention relates to a lens system and a method for controlling anisometropia, and more specifically to a system and method for configuring a lens system to influence the progression of myopia and control anisometropia in patients with at least one myopic eye or a pre-myopic eye. Background Technology

[0002] The following list considers relevant references as background to the currently published topic:

[0003] -1.Chen J, He JC, Chen Y, Xu J, Wu H, Wang F, Lu F, Jiang J. "InterocularDifference of Peripheral Refraction in Anisomyopic Eyes of Schoolchildren".PLoS One.6; 11(2), 2016.

[0004] -2.Deng L, Gwiazda JE. "Anisometropia in children from infancy to15years". Invest Ophthalmol Vis Sci. 20; 53(7): 3782-7, 2012.

[0005] -3.Cheng CY, Yen MY, Lin HY, Hsia WW, Hsu WM. "Association of oculardominance and anisometropic myopia". Invest Ophthalmol Vis Sci. 45(8): 2856-60, 2004.

[0006] -4.Weale RA. "On the age-related prevalence of anisometropia". Ophthalmic Res. 34(6): 389-92, 2002.

[0007] -5.Fu AC,Qin J,Rong JB,Ji N,Wang WQ,Zhao BX,Lyu Y.″Effeets oforthokeratology lens on axial length elongation in unilateral myopia andbilateral myopia with anisometropia children″.Cont Lens Anterior Eye.43(1):73-77,2020.

[0008] -6.Zhong Y,Ke L,Qiong W,Liu F.″Orthokeratology lens for management ofmyopia in anisometropic children:A contralateral study″.Cont Lens AnteriorEye.43(1):40-43,2020.

[0009] -7.Chen Z,Zhou J,Qu X,Zhou X,Xue F;SOS Group.″Effects oforthokeratology on axial length growth in myopic anisometropes″.Cont LensAnterior Eye.41(3):263-266,2018.

[0010] -8.TsaiWS,Wang JH,Lee YC,Chiu CJ.″Assessing the change ofanisometropia in unilateral myopic children receiving monocularorthokeratology treatment″.J Formos Med Assoc.118(7):1122-1128,2019.

[0011] -9.Mutti DO, Hayes JR, Mitchell GL, Jones LA, Moeschberger ML, Cotter SA, Kleinstein RN, Manny RE, Twelker JD, Zadnik K, CLEERE Study Group. "RefractiveError, Axial Length, and Relative Peripheral Refractive Error Before and After the Onset of Myopia". Invest Ophthalmol Vis Sci 48(6):2510-2509, 2007.

[0012] -10. Bullimore MA, Richdale K. "Myopia Control 2020: Where Are We and Who Are We Heading?". Ophthalmic Physiol Opt; 40(3): 254-270.2020.

[0013] -11.Zadnik K, Sinnott LT, Cotter SA, Jones-Jordan LA, Kleinstein RN, MannyRE, Twelker JD, Mutti DO, CLEERE Study Group. "Prediction of Juvenile-OnsetMyopia". JAMA Ophthalmol. 133(6): 683-689, 2015.

[0014] The affirmation of the above references in this article should not be inferred to mean that these references are in any way related to the patentability of the currently disclosed subject matter.

[0015] background

[0016] Anisometropia is a condition where the refractive errors differ between the two eyes. The difference in axial length of the eyes is considered the underlying cause of anisometropia (the more myopic eye is longer and narrower). Any difference in refractive error between the two eyes is detrimental to the patient, and even small differences (e.g., 0.25D or 0.5D) can be considered less severe. Anisometropia is a phenomenon that negatively impacts visual skills and visual development. These negative impacts can include: inappropriate binocular development and impaired stereopsis (the higher the anisometropia, the weaker the binocular function); amblyopia and strabismus (anisometropia is a major cause of amblyopia development, and increasing degrees of anisometropia are associated with a higher risk of developing strabismus); image asymmetry (i.e., a difference in the size or shape of the perceived retinal image between the two eyes); potential intolerance to single-vision (SV) lenses and progressive multifocal (PAL) lenses; and accommodative instability. Therefore, it is recommended to begin treatment for all possible refractive differences between the two eyes as early as possible. The prevalence of anisometropia increases from preschool to adolescence and is associated with the progression of myopia. Currently, the only treatment for anisometropia is orthokeratology lenses, as described in [5-8]. Orthokeratology lenses are generally configured to mechanically affect the curvature of the cornea. However, it is questionable whether optometrists (ECPs) are using orthokeratology lenses to treat anisometropia in clinical practice. There is currently no treatment based on the use of orthokeratology lenses or a proposed solution for anisometropia, meaning that eyeglass lenses or contact lenses provide optical power for visual correction. Summary of the Invention

[0017] Anisometropia, hereinafter, refers to any difference in equivalent spherical power (SER). This invention provides a myopia control lens configured to control anisometropia in a patient with at least one myopic eye or a pre-myopic eye. More specifically, this invention relates to at least one ocular lens for use in eyeglasses or contact lenses configured to control and / or treat (prevent and minimize) anisometropia. The ocular lens of this invention can be used for any anisometropia condition in which at least one eye is myopic or in the pre-myopic stage, regardless of whether the refraction and refraction are spherical and / or astigmatic. The term "controlling anisometropia" hereinafter refers to preventing the progression of differences in refraction between the two eyes of a patient and minimizing existing differences in refraction between the two eyes. This invention is able to affect the progression of myopia differently for each eye, and thus achieve substantially the same level / degree of myopia in both eyes or minimize the differences between the two refractions. This makes it possible to use similar left and right eye myopia control lenses or treatments later (i.e., when both eyes have reached essentially the same level of myopia) to slow the progression of myopia in both eyes at the same rate, if needed.

[0018] Therefore, according to a broad aspect of the invention, a lens system is provided for an individual with anisometropia where each eye has a different refraction (Rx). The lens system includes at least one lens unit having an optical profile defining (1) a central optical zone having optical correction according to the corresponding eye's Rx; and (2) a peripheral zone configured to provide at least one myopia control parameter, which is determined to affect myopia progression differentially for each eye in accordance with a desired amount of anisometropia. The amount of anisometropia refers to the difference between the SER values ​​of the two eyes. The desired amount of anisometropia can be set to a value corresponding to a complete reduction in anisometropia or a difference of 0.25D, 0.5D, 0.75D, or greater than 0.75D. As described above, the at least one lens unit includes at least one ocular lens. The peripheral zone is configured to provide at least one myopia control parameter, which is determined to control anisometropia and make both eyes substantially the same degree of myopia. The at least one myopia control parameter may include any parameter configured to influence and control myopia progression, for example, by affecting peripheral retinal defocus, peripheral blur, chromatic aberration, forming visual cues, and reducing retinal image contrast.

[0019] Each myopia control parameter can be characterized by its myopia control strength, which can vary between 0 (no myopia control strength, e.g., ordinary single vision lenses) and 1 (maximum possible myopia control strength) depending on the specific implementation of the selected myopia control parameter. The myopia control strength of the myopia control parameter can be measured according to refractive power, blur level, number, size, and visual cue density, or any combination thereof, based on the selected myopia control parameter.

[0020] In some embodiments, the lens unit providing at least one myopia control parameter affecting peripheral defocus of the retina is an ocular lens including a myopic peripheral defocus parameter. The myopic peripheral defocus parameter maximizes myopic defocus of light rays from distant objects toward the eye and / or minimizes hyperopic defocus. The lens of the present invention can apply as much myopic defocus as possible at the periphery by placing light rays from distant objects in front of the retina. The term "myopic peripheral defocus parameter" refers, for example, to an optical feature that generates an optical image formed in front of the peripheral retina by adding peripheral power.

[0021] Additional peripheral power can be determined to vary with at least one of the following: anisometropia, Rx per eye, axial length per eye, individual age, rate of myopia progression, or rate of myopia change. The rate of myopia progression can be reflected by the amount of change in SER and / or axial length (e.g., annual change in SER of the less myopic eye relative to the contralateral eye) over a given time period. The rate of myopia change can be reflected by the rate at which the SER and / or axial length of a pre-myopic eye (hyperopic or emmetropic) progresses to a more myopic state over a given time period. The time period is not limited and can be defined as any suitable time period, such as days, months, or years. In specific, non-limiting examples, stronger additional peripheral power is provided for higher levels of anisometropia compared to less severe cases. Alternatively, myopia control lenses with stronger additional peripheral power will be provided for higher refraction compared to lower refraction. Alternatively, a myopia control lens with a stronger additional peripheral power may be provided for a higher rate of myopia progression or rate of myopia change compared to a lower rate of progression. Alternatively, a stronger additional peripheral power may be provided for a higher axial length compared to a shorter axial length. Alternatively, a stronger additional peripheral power may be provided for children than for older patients. The maximum possible strength of the additional peripheral power that can be configured in each case depends on the selected myopia control parameters and the patient's level of compliance with those parameters.

[0022] Generally, anisometropia involves three different scenarios:

[0023] 1. Simple anisometropia: One eye is nearsighted, and the other eye is normal.

[0024] 2. Combined anisometropia: Both eyes are myopic or hyperopic.

[0025] 3. Mixed anisometropia: Both eyes have refractive errors, but one eye is myopic and the other is hyperopic.

[0026] Therefore, the techniques of the currently disclosed subject matter can be implemented accordingly as follows:

[0027] 1. Configure one of the lenses as a myopia control lens to minimize myopia progression in the eye that is more myopic or less hyperopic compared to the contralateral eye. The other lens may or may not be part of the lens system, and the visual requirement is a standard lens corresponding to the less myopic or more hyperopic eye (e.g., with a single-vision optical profile, meaning a single refraction designed to correct central (foveal) vision, without myopia control parameters); and / or

[0028] 2. The lens system comprises two lens units: one lens is a myopia control lens configured with the strongest possible myopia control parameters (e.g., the strongest possible additional peripheral power) for the eye with higher myopia, and the other lens is configured with reduced myopia control parameters (e.g., reduced additional peripheral power for the contralateral eye with lower myopia compared to the additional peripheral power provided to the eye with higher myopia); and / or

[0029] 3. When a hyperopic eye is in the pre-myopic stage and when there is a difference in refractive power between the two eyes, the lenses for the more myopic or less hyperopic eye are configured with adjusted myopia control parameters (e.g., adjustment of additional peripheral power) based on the anisometropia (i.e., the difference in right / left eye refraction and / or axial length), monocular refraction, and / or the axial length of each eye. As mentioned above, the patient's age may also be considered.

[0030] These implementations minimize the difference in central refractive power between the two eyes, which means minimizing anisometropia. In other words, one lens in a lens designed for the eye that initially has weaker myopia or higher hyperopia compared to the other eye is configured to affect the eye's vision through the periphery of the lens, thereby allowing the myopia progression in that eye to develop naturally or be suppressed so that the eye reaches the level of the other eye.

[0031] In some other embodiments, a myopia control lens for eyeglasses is provided, the myopia control lens being configured to differentially influence myopia development / progression based on the initial difference in the patient's compound myopic anisometropic eyes (i.e., the difference in refractive power between the two eyes).

[0032] According to another broad aspect of the currently disclosed subject matter, a method for treating an individual with anisometropia is provided. The method includes obtaining an refraction (Rx) for each eye; calculating the existing anisometropia; determining a desired anisometropia to be achieved, wherein the desired anisometropia is lower than the existing anisometropia; configuring the central optical zone of at least one lens to have optical correction based on the corresponding eye's Rx and determining myopia control parameters for off-center positions to differentially influence myopia progression for each eye in accordance with the desired anisometropia; and configuring the peripheral zone to have the myopia control parameters. In view of this, it should be noted that the method of the currently disclosed subject matter can be implemented by a pre-programmed processing unit or manually by any optometrist (ECP).

[0033] In some implementations, determining the myopia control parameters for non-central locations includes at least one of the myopia control strengths used to determine myopic peripheral defocus parameters.

[0034] Determining myopia control measures based on myopic peripheral defocus parameters may include calculating additional peripheral focal power based on at least one of the following: anisometropia, Rx for each eye, axial length for each eye, individual age, rate of myopia progression, or rate of myopia change.

[0035] In some implementations, the method further includes identifying the eye with more myopia or less hyperopia compared to the contralateral eye.

[0036] In some implementations, determining myopia control parameters for non-central locations includes minimizing myopia progression in the eye that is more myopic than the contralateral eye or less hyperopic than the contralateral eye.

[0037] In some embodiments, the method further includes configuring at least one lens unit to have determined myopia control parameters with a central optical zone and an off-center position.

[0038] In some embodiments, the method further includes configuring at least one ocular lens unit to include at least one spectacle lens or at least one contact lens.

[0039] In some embodiments, the technology further includes configuring a second lens unit. The second lens unit may have a single-vision optical property profile corresponding to an eye that is less myopic or more hyperopic compared to the contralateral eye.

[0040] In some embodiments, the technology further includes configuring a second lens unit to have an optical property profile that defines (1) a central optical zone with optical correction according to the corresponding eye's Rx; and (2) a peripheral zone configured to provide myopia control parameters that are configured to affect the progression of myopia differently for each eye.

[0041] In some implementations, determining the myopia control parameters of the first lens unit includes adapting a stronger additional peripheral power to the eye that is more myopic than the contralateral eye; and configuring the second lens unit to have a reduced additional peripheral power compared to the contralateral lens unit.

[0042] In some implementations, the method also includes obtaining the individual's age.

[0043] In some implementations, the method further includes calculating, based on at least one of the individual's age, the corresponding eye's axial length, Rx, rate of myopia progression, or rate of myopia change, a reduced additional peripheral power for the less myopic or more hyperopic eye compared to the additional peripheral power calculated for the less myopic or more hyperopic eye.

[0044] In some embodiments, the method further includes: obtaining a second refraction (Rx) for each eye, and after both eyes have substantially the same degree of myopia, configuring the central optical zone of each lens to have optical correction according to the Rx of the corresponding eye and determining the optical properties of the off-center position to influence and control the myopia progression to be similar in both eyes.

[0045] According to another broad aspect of the currently disclosed subject matter, a processing unit is provided for providing a personalized lens optical property profile. The processing unit includes: a data input device configured and operable to receive a specific refraction (Rx) for each eye of an individual; a data analyzer configured and operable to calculate an existing anisometropia, determine a desired anisometropia to be achieved, wherein the desired anisometropia is lower than the existing anisometropia; configuring a central optical zone of at least one lens to have optical correction according to the corresponding eye's Rx, and determining myopia control parameters at off-center locations to differentially influence the progression of refractive error (according to the refraction) for each eye in relation to the desired anisometropia; configuring a peripheral zone to have the myopia control parameters; and a data output device configured and operable to provide a lens optical property profile defining a central optical zone with optical correction according to the corresponding eye's Rx and a peripheral zone having the myopia control parameters.

[0046] In some implementations, the data analyzer is configured and operable to determine the myopia control parameters for the off-center location by determining at least one of myopic peripheral defocus, peripheral blur, chromatic aberration, forming visual cues, or reducing retinal image contrast.

[0047] In some implementations, the data analyzer is configured and operable to determine the degree of myopia control for selected myopia control parameters.

[0048] In some implementations, the myopia control parameter is a myopic peripheral defocus parameter, and determining the myopia control strength includes determining the additional peripheral focal power.

[0049] In some implementations, the data analyzer is configured and operable to determine the additional peripheral focal length by calculating the additional peripheral focal length based on at least one of anisometropia, Rx per eye, axial length per eye, individual age, rate of myopia progression, or rate of myopia change.

[0050] In some implementations, the data analyzer is configured and operable to identify the eye with more myopia or less hyperopia compared to the contralateral eye, and to determine myopia control parameters for non-central locations by minimizing myopia progression in the eye with more myopia or less hyperopia compared to the contralateral eye.

[0051] In some implementations, the data analyzer is configured and operable to configure at least one lens unit with determined myopia control parameters for a central optical zone and an off-center position.

[0052] In some embodiments, the data analyzer is configured and operable to configure at least one lens unit to include at least one spectacle lens or at least one contact lens.

[0053] In some implementations, the data analyzer is configured and operable to configure the second lens unit.

[0054] In some implementations, the data analyzer is configured and operable to configure the second lens unit to have a single-vision optical property profile corresponding to an eye that is less myopic or more hyperopic compared to the contralateral eye.

[0055] In some embodiments, the data analyzer is configured and operable to configure the second lens unit to have an optical property profile that defines (1) a central optical zone having optical correction according to the Rx of the corresponding eye; and (2) a peripheral zone configured to provide myopia control parameters that are configured to affect myopia progression differently for each eye.

[0056] In some implementations, the data analyzer is configured and operable to determine the myopia control parameters of the first lens unit by adapting a stronger additional peripheral power to the eye that is more myopic than the contralateral eye and configuring the second lens unit to have a reduced additional peripheral power compared to the contralateral lens unit.

[0057] In some implementations, the data input device is configured and operable to receive an individual's age.

[0058] In some implementations, the data analyzer is configured and operable to determine the reduced additional peripheral power based on at least one of anisometropia, myopia progression rate, myopia change rate, axial length of the corresponding eye, individual age, or Rx of the corresponding eye.

[0059] In some implementations, the data analyzer is adapted to configure the central optical zone of each lens to have optical correction according to the Rx of the corresponding eye after both eyes have substantially the same degree of myopia, and to determine the optical properties of the off-center location to influence and control the myopia progression to be similar in both eyes. Attached Figure Description

[0060] To better understand the subject matter disclosed herein and to illustrate how the subject matter can be practically implemented, embodiments will now be described by way of non-limiting example only with reference to the accompanying drawings, in which:

[0061] Figure 1 This is a schematic diagram of a possible cross-sectional view of the currently disclosed subject matter;

[0062] Figure 2 It is a schematic block diagram of a processing unit based on a broad aspect of the currently disclosed subject matter; and

[0063] Figure 3 This is a schematic flowchart illustrating a method for configuring lenses for treating at least one eye of an individual suffering from anisometropia, based on another broad aspect of the currently disclosed subject matter. Detailed Implementation

[0064] refer to Figure 1The diagram illustrates a cross-sectional view of the lens system of the subject matter currently disclosed. The lens system 10 is configured to influence and control myopia progression in the eyes of an individual with anisometropia (i.e., each eye has a different refraction (Rx)). Typically, the refraction Rx includes various optical parameters, including at least one of spherical power, cylindrical power and axial value, additional focal power, or prism power. The lens system 10 includes at least one lens unit 10A, which comprises an optically contoured area defining (1) a central optical zone having optical correction according to the corresponding eye's Rx, referred to in the diagram as zone C1; and (2) a peripheral zone referred to in the diagram as zone P1, the peripheral zone being configured to provide at least one myopia control parameter determined to influence myopia progression differently for each eye. It should be noted that the illustration is not limiting and the diagram does not represent the exact size, shape, or location of the different zones. The at least one myopia control parameter and its myopia control strength are typically selected based on the desired reduction in the rate of myopia progression associated with the desired amount of anisometropia. In a specific, non-limiting example, the myopia control parameters are defined by the refractive power of peripheral refraction. Therefore, the myopia control parameters may include any parameters of a transconjunctival lens configured to influence and control myopia progression by, for example, myopic peripheral defocus caused by additional peripheral power, creating peripheral blur, affecting chromatic aberration, creating visual cues, and reducing retinal image contrast. The myopia control parameters can be changed at various treatment stages according to treatment progress. For example, in a myopia control lens designed based on additional peripheral power, the additional peripheral power P1 of the lens may be configured to be at least 1D and can be changed at various treatment stages according to treatment progress. The optical profile of the lens system 10 is customized for each individual and is based on the individual's refraction. The lens unit 10A may be a transconjunctival lens integrated into eyeglasses or contact lenses. As described above, the peripheral region P1 of the lens unit 10A is configured to provide at least one myopia control parameter configured to control anisometropia and achieve substantially the same degree of myopia in both eyes. The at least one myopia control parameter includes at least one of the following: a myopic peripheral defocus parameter with additional peripheral power, an optical feature that causes peripheral blurring, an optical feature that affects chromatic aberration, an optical feature that creates visual cues, or an optical feature that reduces the contrast of the retinal image. The degree of myopia control for each myopia control parameter can be determined to vary with at least one of the following: anisometropia, Rx per eye, rate of myopia progression or rate of myopia change, axial length of each eye, or individual age.

[0065] In some embodiments, the lens system 10 further includes a second lens unit 10B. The second lens unit 10B may have a single-vision optical property profile corresponding to an eye with less myopia or more hyperopia compared to the contralateral eye. Alternatively, the second lens unit 10B may have an optical property profile that defines (1) a central optical zone having optical correction according to the corresponding eye's Rx, the central optical zone being referred to as zone C2 in the figure; and (2) a peripheral zone configured to provide myopia control parameters, the peripheral zone being referred to as zone P2 in the figure, the myopia control parameters being determined to affect myopia progression differently for each eye.

[0066] refer to Figure 2This diagram illustrates a schematic block diagram of a processing unit for providing profiles of the optical properties of personalized lenses, based on a broad aspect of the currently disclosed subject matter. The processing unit 200 includes a computer system comprising a data analyzer 206 and is part of and connected to a computer network. The processing unit 200 may include a general-purpose computer processor programmed in software to perform the functions described below. Unless otherwise specifically stated, it should be understood from the following discussion that throughout the description, terms such as “determine,” “correlate,” “compare,” “calculate,” and “process” are used to refer to computer actions and / or processes that manipulate data and / or transform data into other data. Furthermore, operations according to the teachings herein can be performed by a computer specifically constructed for the desired purpose or by a general-purpose computer specifically configured to achieve the desired purpose via a computer program stored on a computer-readable storage medium. Processing unit 200 includes: a data input device 202 including a communication module for receiving a routine refraction (Rx) of each eye of an individual and optionally receiving the individual's age; an optional memory (i.e., a non-volatile computer-readable medium) 204 storing input / output data, a database, or a computer program, as detailed below; and a data analyzer 206 adapted to calculate existing anisometropia, determine a desired anisometropia to be achieved, configure the central optical zone of at least one lens to have optical correction according to the corresponding eye's Rx, determine myopia control parameters for off-center locations to affect myopia progression differently for each eye in relation to the desired anisometropia, and configure the peripheral zone to have myopia control parameters; and a data output device 208 configured and operable to provide a lens optical property profile that defines a central optical zone with optical correction according to the corresponding eye's Rx and a peripheral zone with myopia control parameters. The memory 204 may be integrated within the processing unit 200, or it may be an external storage device accessible by the processing unit 200. For example, the software may be downloaded electronically to the analyzer 206 via a network, or alternatively, the software may be provided on a tangible medium, such as an optical memory medium, a magnetic memory medium, or an electronic memory medium. The processing unit 200 includes at least one computer entity linked to a server via a network, wherein the network is configured to receive and respond to requests sent via the network, and also, in response to requests, transmit one or more modules of computer-executable program instructions and displayable data to a networked user computer platform, wherein the modules include modules configured to receive and transmit optical property information to recommend, based on a calculated associated transmission lens profile, for display by the networked user computer platform.The disclosed subject matter may include computer program instructions stored in a local storage device, which, when executed by processing unit 200, cause processing unit 200 to receive an individual's optometric data and / or age data and determine at least one optical property of a lens. The computer program product may be stored on a tangible computer-readable medium, including a library of software modules that causes a computer to execute the library to prompt information related to optical lens profile recommendations and to store or display such recommendations. The computer program may be stored in the memory 204 of processing unit 200 or in a removable memory medium suitable for cooperation with a reader of processor unit 200, and includes instructions for implementing the methods described below. More specifically, the computer program may communicate with an interface to receive optometric data.

[0067] In some embodiments, data analyzer 206 is configured and operable to configure at least one lens unit to have determined myopia control parameters for a central optical zone and an off-center location. This can be implemented by determining the myopia control parameters for the off-center location and defining the myopia control strength of the determined myopia control parameters. For example, data analyzer 206 is configured and operable to determine the myopia control parameters for the off-center location by minimizing myopia progression in the eye that is more myopic than the contralateral eye or less hyperopic than the contralateral eye. Alternatively, data analyzer 206 is configured and operable to determine the myopia control parameters for the first lens unit by adapting a stronger additional peripheral power for the eye that is more myopic than the contralateral eye and configuring the second lens unit to have a reduced additional peripheral power compared to the contralateral lens unit. Alternatively, data analyzer 206 is configured and operable to determine the reduced additional peripheral power based on at least one of anisometropia, myopia progression rate, myopia change rate, axial length of the corresponding eye, individual age, or Rx of the corresponding eye. In specific, non-limiting examples, in cases where the rate of myopia progression is relatively high in the eye with milder myopia, the additional peripheral power can be reduced, but the reduction will be less than in cases with a moderate rate of myopia progression. After both eyes have substantially the same degree of myopia, the data analyzer 206 is adapted to configure the central optical zone of each lens to have optical correction according to the corresponding eye's Rx, and to determine the optical properties of the off-center locations to influence and control the myopia progression to be similar in both eyes.

[0068] Table 1 below represents examples of the normalization strength of myopia control parameters for eyes with severe myopia in different age groups:

[0069]

[0070] Table 1

[0071] Therefore, it should be understood that the normalization value of the myopia control parameter varies between 0 and 1, where 0 represents no myopia control (e.g., with ordinary single-vision lenses), and 1 represents the maximum possible myopia control for the selected myopia control parameter. Furthermore, these values ​​are empirical approximations, representing values ​​within a range of + or -10% and should not be considered absolutely precise. The maximum possible myopia control for the lens is determined based on the instructions for the selected myopia control parameter and the patient's compliance. Normalization of values ​​within the range can be linear, logarithmic, exponential, polynomial, or power normalization, depending on the characteristics of the selected myopia control parameter. The selection of an appropriate value is determined based on several parameters, including the patient's age, their initial refraction, or the expected reduction in the rate of myopia progression. On the one hand, high myopia control parameter values ​​can introduce distortions or aberrations, increasing blurred perception and impairing the patient's ability to see through them. On the other hand, low myopia control parameter values ​​may not be sufficient to affect myopia progression. Therefore, the selection of values ​​for myopia control parameters allows for the control of individual myopia progression for each specific patient, including the desired anisometropia and rate of myopia development. The different proposed theoretical values ​​in this example and the examples described below do not limit lens configurations to taking into account several other parameters, such as those typically related to the lens manufacturing technology.

[0072] Table 2 below shows examples of the normalization strength of the myopia control parameters for different age groups and for both eyes:

[0073]

[0074] Table 2

[0075] As mentioned above, Table 2 illustrates one implementation of the currently disclosed subject matter, namely, reducing the myopia control intensity of the myopia control parameters of the contralateral, less myopic eye compared to the myopia control intensity provided to the more myopic eye.

[0076] As described above, in some embodiments, the additional peripheral power can be determined to vary with the rate of myopia progression or rate of myopia change relative to the contralateral eye, whether the eye with less myopia or more myopia. Table 3 below illustrates one embodiment of the currently disclosed subject matter, namely, reducing the myopia control force of the myopia control parameters for the contralateral eye with less myopia compared to the myopia control force provided for the more myopic eye. Specifically, Table 3 represents examples of normalized forces of myopia control parameters prescribed for both eyes based on different annual progression rates for the less myopic eye. As illustrated in the table for higher myopia progression rates, the myopia control lens is configured to have a stronger additional peripheral power compared to lower progression rates.

[0077]

[0078] Table 3

[0079] Table 4 below represents examples of additional peripheral focal power for myopic peripheral defocus parameters prescribed for eyes with severe myopia in different age groups:

[0080]

[0081] Table 4

[0082] In this example in Table 4, the maximum focal length conformity was determined to be +4D. For example, the younger the age, the stronger the additional peripheral focal length should be compared to the additional peripheral focal length given for an older age.

[0083] In this specific, non-limiting example, the less myopic eye (i.e., the contralateral eye) may have a single-vision lens with its own refraction until the anisometropia is completely reduced or reduced to 0.25D, 0.5D, 0.75D, or 1.00D (the difference between binocular refraction). Then, myopia control lenses may be fitted for both eyes.

[0084] The following are several non-limiting examples of lens configurations, namely, lens power distribution maps and the relationship between visual acuity (refraction) and lens maps; and examples of different maps for different eyes based on the values ​​defined in Tables 1 to 3 above.

[0085] A six-year-old's refraction test revealed a refractive error of -0.25D in the right eye and -1.50D in the left eye. Processing unit 200 calculated the anisometropia to be 1.25D and determined that the desired anisometropia should be minimized as much as possible. Processing unit 200 identified the right eye as having milder myopia and configured the right eye's lens as a "standard lens" (i.e., a single-vision lens with a refractive power of -0.25D), and configured the left eye's lens as a central lens with a refractive power of -1.50D and a peripheral lens with an additional peripheral power of +3D for myopic peripheral defocus. As the difference between the two eyes decreases, both lenses can be configured as myopia control lenses with an additional peripheral power of +3D in the peripheral area.

[0086] For the same subject, under identical refraction conditions, the right eye lens can be configured as a "standard lens" (i.e., a single-vision lens with a refractive power of -0.25D), and the left eye lens is configured with a central refractive power of -1.50D and myopia control parameters that reduce retinal image contrast, wherein the peripheral contrast is reduced by 50% relative to the image contrast observed using the lens's aperture. When the difference between the two eyes decreases, both lenses can be configured as myopia control lenses with a 50% reduction in peripheral contrast relative to the image contrast observed using the lens's aperture to best control binocular myopia.

[0087] In another specific, non-limiting example where the right eye has a refractive error of -5.00D and the left eye has a refractive error of -7.50D, the processing unit 200 identifies the less myopic eye as the right eye and configures the lens for the right eye as a "standard lens" (i.e., a single-vision lens with a refractive power of -5.00D), and the lens for the left eye can be configured to have a central area with a refractive power of -7.50D and a peripheral area with a myopic peripheral defocus parameter of +3D. It should be noted that in this example, age is not taken into account due to the anisometropia and high myopia. The additional peripheral power is determined to be the maximum value (e.g., +3D). This example can be given for any age.

[0088] When the difference between the two eyes is reduced, the lenses for both eyes can be configured as myopia control lenses with an additional focal power of +3D in the peripheral area.

[0089] For the same subject, under identical refraction conditions, due to high refraction and anisometropia, the right eye's lens is configured as a "standard lens" (i.e., a single-vision lens with a diopter of -5.00D), and the left eye's lens is configured with a central diopter of -7.50D and myopia control parameters that reduce retinal image contrast, wherein peripheral contrast is reduced by 60% relative to the image contrast observed using the lens's aperture. When the difference between the two eyes decreases, both lenses can be configured as myopia control lenses with a 50% reduction in peripheral contrast relative to the image contrast observed using the lens's aperture to best control binocular myopia.

[0090] As described above, a second embodiment of the currently disclosed subject matter involves fitting one lens with the strongest or sufficiently strong additional peripheral power for the more myopic eye and fitting another lens with a reduced additional peripheral power for the contralateral less myopic eye. This lower peripheral angle can be adjusted according to the patient's age and the refraction of the less myopic eye, and can be changed and adjusted at some stage of treatment based on the myopia progression, rate of myopia progression, or rate of myopia change in each eye. When the anisometropia is completely reduced or reduced to 0.25D, 0.5D, 0.75D, or 1.00D (difference between binocular refraction), myopia control lenses with the same peripheral angle or single-vision lenses are fitted to both eyes.

[0091] In a specific, non-limiting example of a seven-year-old individual with -0.25D refractive error in the right eye and -1.50D refractive error in the left eye, the lens for the right eye is configured with a central zone of -0.25D and a peripheral zone of +1.5D additional power to control myopia, but with weaker power compared to the more myopic eye. The lens for the left eye is configured with a central zone of -1.50D and a peripheral zone of +2.5D additional power. This additional power is provided to prevent further myopia progression in the more myopic eye. When the difference between the two eyes decreases, the lenses for both eyes can be configured as myopia control lenses with a peripheral zone of +3D additional power for optimal control of binocular myopia.

[0092] In specific, non-limiting examples, for the same subject, under the same refraction conditions, if the annual rate of myopia progression in the right eye is 1.00D, then the lens for the right eye can be configured to have a central zone with a refractive power of -0.25D and a peripheral zone with an additional power of +1.50D to control myopia, and the lens for the left eye can be configured to have a central zone with a refractive power of -1.50D and a peripheral zone with an additional power of +2.50D.

[0093] However, if the annual myopia progression rate of the right eye is 0.50D, the lens for the right eye can be configured with a central zone of -0.25D and a peripheral zone of +1.00D to control myopia, and the lens for the left eye can be configured with a central zone of -1.50D and a peripheral zone of +2.25D. When the difference between the two eyes decreases, the lenses for both eyes can be configured with myopia control lenses having a peripheral zone of +3D to optimize myopia control in both eyes.

[0094] In another specific, non-limiting example, for the same subject, under identical refraction conditions, the lens for the right eye can be configured with a central diopter of -0.25D and myopia control parameters that reduce retinal image contrast, wherein peripheral contrast is reduced by 40% relative to the image contrast observed using the lens's aperture. The lens for the left eye can be configured with a central diopter of -1.50D and myopia control parameters that reduce retinal image contrast, wherein peripheral contrast is reduced by 50% relative to the image contrast observed using the lens's aperture. When the difference between the two eyes decreases, the lenses for both eyes can be configured as myopia control lenses with a 50% reduction in peripheral contrast relative to the image contrast observed using the lens's aperture to optimize the control of myopia in both eyes.

[0095] In another specific, non-limiting example, with a refractive error of -4.5D in the right eye and -7.00D in the left eye, the lens for the right eye is configured with a central area of ​​-4.5D and a peripheral area with an additional power of +2D, and the lens for the left eye is configured with a central area of ​​-7.00D and a peripheral area with an additional power of +3D. Furthermore, in this example, age is not taken into account due to the high anisometropia and myopia. The additional peripheral power is determined to be the maximum value (e.g., +3D). This example can be given for any age.

[0096] When the difference between the two eyes is reduced but anisometropia still exists, in order to properly treat myopia in both eyes, the difference between the additional optical power between the eyes can be reduced, and thus the right eye can have a myopia control lens with an additional peripheral power of +2.5D and the left eye can have a myopia control lens with an additional peripheral power of +3D.

[0097] When the anisometropia is completely reduced or reduced to 0.25D, 0.5D, 0.75D or 1.00D (difference between binocular refraction), myopia control lenses can be configured for both eyes with an additional peripheral power of +3D.

[0098] As described above, the third implementation of the currently disclosed subject matter technique is to prevent the development of anisometropia by using this treatment at an early stage when the child is not yet myopic but the peripheral refractive error of the retina begins to become hyperopic. Researchers have found that children who become myopic all had hyperopic peripheral refractive errors for 1 to 2 years before the onset of myopia [9], and myopia can be well predicted based on the refractive error being <+0.75D at age 6, <+0.50D at age 7 to 8, <+0.25D at age 9 to 10, and below plano at age 11 [10, 11]. In these cases, when there is a refractive error between the two eyes and at least one eye appears to be becoming myopic or is in the pre-myopic stage, the eye with more severe myopia or less severe hyperopia can be configured to wear a myopia control lens and the contralateral eye can have a plano SV lens. The refraction can be adjusted according to the development of the refraction in both eyes. The myopia control parameters of the lenses can be adapted based on the child's age, anisometropia (difference in right / left eye refraction and / or axial length), monocular refraction, axial length of each eye, and / or rate of myopia change. The treatment plan is suitable for children with anisometropia of 0.25D, 0.5D, 0.75D, 1.00D, 1.25D, 1.50D, or greater between the two eyes.

[0099] Based on the broad scope of the currently disclosed subject matter, a method is provided for configuring lenses for treating anisometropia (refractive error) of some degree. Reference Figure 3The main steps of the method 300 of the disclosed subject matter are illustrated by a flowchart. Method 300 includes: obtaining refraction (Rx) for each eye and optionally obtaining the individual's age; in 302, determining the optical properties of a lens; in 304, calculating an existing anisometropia A1; in 306, configuring the central optical zone of at least one lens to have optical correction according to the corresponding eye's Rx; and in 308, determining myopia control parameters at off-center locations to affect myopia progression differently for each eye corresponding to a desired anisometropia A2.

[0100] In some implementations, method 300 further includes: configuring at least one lens unit to have a central optical zone in 314; and determining myopia control parameters for a non-central location.

[0101] In some implementations, method 300 includes an initial step of measuring the refraction (Rx) of at least one eye in 310. Optionally, method 300 may include storing all data into a database in 316.

Claims

1. A lens system for an individual having anisometropia, the lens system comprising a first lens for a first eye of the individual and a second lens for a second eye, the first and second lenses being eyeglasses or contact lenses, wherein: the first lens and the second lens are characterized by a first refraction for the first eye and a second refraction for the second eye, the first and second refractions defining an existing amount of anisometropia; the first lens has an optical property profile defining (1) a central optical zone having a given first individual refraction power of the first eye and (2) a peripheral zone configured to provide a myopia control parameter having a selected first myopia control strength; the second lens has an optical property profile defining one of (i) a central optical zone having a given second individual refraction power and a peripheral zone configured to provide a myopia control parameter having a selected second myopia control strength lower than the selected first myopia control strength or (ii) a single vision optical property profile having the given second individual refraction power and no myopia control strength; a difference between the first myopia control strength and the second myopia control strength is determined according to a desired amount of anisometropia to be obtained and lower than the existing amount of anisometropia defined by a difference between the first individual refraction power of the first eye and the second individual refraction power of the second eye, thereby ensuring that the optical property profile of the first lens and the optical property profile of the second lens combined are capable of controlling anisometropia to bring the first eye and the second eye to the desired amount of anisometropia.

2. The lens system of claim 1, wherein the myopia control parameter comprises at least one of a myopic peripheral defocus parameter having an additional peripheral power, an optical feature forming a peripheral blur, an optical feature affecting chromatic aberration, an optical feature forming a visual cue, or an optical feature reducing retinal image contrast.

3. The lens system of claim 1 or 2, wherein the myopia control parameter comprises a myopia control strength determined to vary with at least one of an amount of anisometropia, an Rx of each eye, a rate of myopia progression, a rate of myopia change, an axial length of each eye, or an age of the individual.

4. The lens system of any of the preceding claims, wherein the myopia control parameter is configured to minimize myopia progression of an eye that is more myopic or less hyperopic compared to the contralateral eye.

5. The lens system of any of claims 1 to 3, wherein the myopia control parameter of the first lens is configured to fit a stronger additional peripheral power compared to the second eye, and the myopia control parameter of the second lens is configured to have a reduced additional peripheral power compared to the contralateral lens.

6. The lens system of claim 5, wherein the additional peripheral power is determined according to at least one of an age of the individual or a refraction of the corresponding eye.

7. The lens system of any one of claims 1 to 3, wherein the difference between the given personal prescription power of the first lens and the given personal prescription power of the second lens is higher than 1.00 D.

8. The lens system of any one of claims 1 to 3, wherein at least one of the first myopia control parameter and the second myopia control parameter is selected to achieve a desired reduction in the refractive disparity, wherein the desired reduction in the refractive disparity is set to a value corresponding to a full reduction in the refractive disparity or to a difference of 0.25 D, 0.5 D, 0.75 D, or higher than 0.75 D.

9. A method for designing a lens system comprising a first lens for a first eye and a second lens for a second eye of an individual suffering from a refractive disparity, the first and second lenses being spectacles or contact lenses, the method comprising: obtaining a first prescription for the first eye and a second prescription for the second eye of the individual, respectively; calculating an existing amount of refractive disparity; determining a desired amount of refractive disparity to be achieved, wherein the desired amount of refractive disparity is lower than the existing amount of refractive disparity; determining a desired amount of refractive disparity to be achieved that is lower than the existing amount of refractive disparity and defining a difference between a selected first myopia control strength of the first lens and a selected second myopia control strength of the second lens to be provided based on the desired amount of refractive disparity; determining an optical property profile for the first lens, the optical property profile for the first lens defining a central optical zone having a given first personal prescription power and a peripheral zone configured to provide a myopia control parameter having the selected first myopia control strength; determining an optical property profile for the second lens, the optical property profile for the second lens defining one of: (i) a central optical zone having a given second personal prescription power and a peripheral zone configured to provide a myopia control parameter having the selected second myopia control strength that is lower than the selected first myopia control strength; or (ii) a single vision optical property profile having the given second personal prescription power and no myopia control parameter and no myopia control strength, the optical property profile of the first lens and the optical property profile of the second lens in combination thereby enabling control of the refractive disparity to bring the first eye and the second eye to the desired amount of refractive disparity.

10. The method of claim 9, wherein the determination of the myopia control parameter comprises determining at least one of a myopic peripheral defocus, a peripheral blur, a chromatic aberration, creating a visual cue, or reducing retinal image contrast.

11. The method of claim 9 or 10, wherein the myopia control strength comprises an additional peripheral power.

12. The method of claim 11, wherein the additional peripheral power is determined as a function of at least one of an amount of refractive disparity, the first prescription and the second prescription, a rate of progression of myopia, a rate of change of myopia, an axial length of each eye, or an age of the individual.

13. A processing unit for designing a lens system for manufacturing purposes, the lens system comprising a first lens for a first eye of an individual suffering from anisometropia and a second lens for a second eye, the first and second lenses being spectacles or contact lenses, the processing unit comprising: a data input device configured and operable to receive a first refraction for the first eye and a second refraction for the second eye of the individual, respectively; a data analyzer configured and operable to perform the following: determine an existing amount of anisometropia from the first refraction and the second refraction, and determine a desired amount of anisometropia to be achieved, wherein the desired amount of anisometropia is lower than the existing amount of anisometropia, and define a difference between a selected first amount of myopia control of the first lens and a selected second amount of myopia control of the second lens to be provided based on the desired amount of anisometropia; determine an optical property profile of the first lens and an optical property profile of the second lens such that the optical property profile of the first lens and the optical property profile of the second lens in combination control anisometropia to achieve the desired amount of anisometropia for the first eye and the second eye, wherein: the optical property profile for the first lens is determined to define a central optical zone having a given first personal refraction power and a peripheral zone configured to provide a myopia control parameter having the selected first amount of myopia control; and the optical property profile for the second lens is determined to define one of: (i) a central optical zone having a given second personal refraction power and a peripheral zone configured to provide a myopia control parameter having the selected second amount of myopia control lower than the selected first amount of myopia control; or (ii) a single vision optical property profile having the given second personal refraction power and no myopia control parameter and no amount of myopia control.

14. The processing unit of claim 13, wherein the data analyzer is configured and operable to determine the myopia control parameter by determining at least one of myopic peripheral defocus, peripheral blur, chromatic aberration, creating a visual cue, or reducing retinal image contrast.

15. The processing unit of claim 13 or 14, wherein the amount of myopia control comprises an additional peripheral power.

16. The processing unit of claim 15, wherein the data analyzer is configured and operable to determine the additional peripheral power as a function of at least one of an amount of anisometropia, Rx of each eye, rate of myopia progression, rate of change of myopia, axial length of each eye, or age of the individual.

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