Ophthalmic lens

Abstract

A method for determining the gradient length (LP) of an ophthalmic lens, implemented by a computer device, comprising the steps of: - providing an under-illuminated value Add (21), - providing a model (22) that associates the under-illuminated value Add with the gradient length (LP), - determining the gradient length (23) based on the model and the provided under-illuminated value.

Description

Technical Field

[0001] This disclosure relates to a method, implemented via a computer device, for determining the gradient length of an ophthalmic lens intended to be worn in front of a user's eye. This disclosure also relates to a method, implemented via a computer device, for providing surface data of an ophthalmic lens intended for use in manufacturing the lens. Additionally, this disclosure relates to an associated optical element. Background Technology

[0002] Wearers with lower addendum values ​​are often new progressive lens wearers. These new progressive lens wearers are not accustomed to lowering their gaze direction for near tasks. Therefore, they need easy access to the near vision zone while maintaining comfortable and open vision within it.

[0003] Typically, individuals who need eyeglasses and require a prescription from an ophthalmologist or optometrist go to an optician's shop. The optician orders a pair of lenses that correspond to the wearer's prescription. These lenses, delivered to the optician, are designed and manufactured according to optical standards. In the case of progressive lenses, this lens is designed to determine the location and extent of both the distance and near vision zones. In particular, the location of the near vision zone is important for these new progressive lens wearers.

[0004] The choice of eyeglass frames imposes certain limitations on determining the location of the near vision zone.

[0005] Typically, the selection of the near vision zone is made by the optician based on subjective criteria (such as lens height, wearer's posture, or feedback from the wearer to their previous device).

[0006] The location of the near vision zone can also be determined by measuring near vision behavior to ensure a perfect fit for the wearer. This measurement is performed by an optician. However, this measurement requires not only the optician to spend time with the wearer in the store, but also mandatory training to be conducted before it can be performed.

[0007] Therefore, there is a need for a progressive lens that allows easy access to the near vision zone and provides high visual comfort, while requiring less subjective selection and time-consuming measurements by the optician. Summary of the Invention

[0008] Therefore, this disclosure proposes a method, implemented via a computer device, for determining the gradient length of an ophthalmic lens intended to be worn in front of a user's eye, the method comprising the following steps:

[0009] - Provides the additional light value (Add).

[0010] - Provides a model that correlates the downlight value Add with the gradient length.

[0011] - Based on the model and the provided underlight value, determine the gradient length.

[0012] Ophthalmic lenses are progressive ophthalmic lenses.

[0013] An ophthalmic lens has two surfaces: a front surface and a back surface. At least one surface of an ophthalmic lens includes at least:

[0014] The field of view region with a field of view reference point (FVP)

[0015] Near region with near reference point NVP,

[0016] The principal gradient meridian, which passes through at least the far-viewing reference point FVP and the near-viewing reference point NVP, defines the vertical axis by the portion of the principal gradient meridian that crosses the far-viewing region.

[0017] Prescription FC (Cross-face)

[0018] The prism reference point serves as the origin of a reference frame with a y-axis, which allows for the definition of a y-axis value relative to the vertical axis for each point on the lens.

[0019] The gradient length LP corresponds to the difference between the value of the lens fitting cross FC on the y-axis and the value of the near reference point NVP on the y-axis.

[0020] The ophthalmic lens also has a first average power value P1 at the distance reference point FVP and a second average power value P2 at the near reference point NVP. The ophthalmic lens includes an add value Add corresponding to the difference between the first average power value P1 and the second average power value P2.

[0021] The provided downlight value and gradient length LP can be associated with ophthalmic lenses.

[0022] The user's eye can be the user's right eye, or the user's left eye, or the user's virtual right eye, or the user's virtual left eye, or the user's central eye.

[0023] In the context of this invention, "virtual eye" refers to a digital representation of the user's eye. This digital representation can be, for example, a point with three coordinates, such as the center of eye rotation. This digital representation can optionally include a prescription.

[0024] In the context of this invention, the user's central eye is a virtual eye that serves as a reference for the user's binocular visual system. This central eye is positioned by default at the center of rotation of the two eyes, but it can be positioned at other locations on the line segment connecting the centers of rotation of the two eyes, for example, depending on visual dominance.

[0025] According to other embodiments that may be considered individually or in combination, the ophthalmic lens may be a real ophthalmic lens or a virtual ophthalmic lens designed to be worn in front of a user's virtual eyes.

[0026] In the context of this invention, "virtual ophthalmic lens" means a digital representation of an ophthalmic lens (in space and / or in optical power / surface power).

[0027] Advantageously, by determining the gradation resulting from the under-illuminated power, the method of this disclosure allows for the avoidance of additional measurements by the optician. Indeed, the inventors have demonstrated that, without separate measurements by the optician, the under-illuminated power is one of the most relevant parameters available for estimating the wearer's fit to progressive lenses, and that there is a correlation between the under-illuminated power and the gradation length. Furthermore, using the user's under-illuminated power is highly effective in providing a good trade-off between near entry (in other words, easier near entry with a shorter gradation length) and optical distortion associated with power gradation (in other words, lower distortion with higher PL): a lower under-illuminated power will allow for a lower gradation length, as a lower under-illuminated power will create a good near entry with acceptable distortion.

[0028] According to other embodiments that may be considered individually or in combination, the gradient length (LP) is the virtual gradient length of the virtual ophthalmic lens.

[0029] According to other embodiments that can be considered individually or in combination,

[0030] The model includes a first sub-model and a second sub-model, and

[0031] The steps to determine the gradient length include:

[0032] - Provides a first sub-model that associates the downlight value Add with a reduction in the gaze angle.

[0033] -Based on the first sub-model and the provided additional light value, determine the reduction in gaze angle.

[0034] - Provide a second sub-model that correlates the gaze angle reduction with the gradient length.

[0035] The gradient length (LP) is determined based on the second sub-model and the reduced gaze angle. The concept of “reduced gaze angle” is known to those skilled in the art, and is explained in particular in the referenced patent document WO 2015 / 074777 A1.

[0036] According to another embodiment, which can be considered alone or in combination, the eye is a central eye. In this embodiment, the ophthalmic lens worn in front of the user's central eye is a virtual ophthalmic lens.

[0037] Advantageously, this embodiment allows for a common reference between the two eyes and can improve the binocular performance of an ophthalmic lens by taking into account the central eye.

[0038] According to other embodiments that can be considered individually or in combination, based on the model, the gradient length PL increases with the added light value. Advantageously, even with a high added light value, the transition between the distance and near vision regions remains comfortable.

[0039] According to other embodiments that can be considered individually or in combination, the model is based on the user's prescription or on a statistical database.

[0040] According to other embodiments that can be considered individually or in combination, the model is linear and limited by the maximum gradient length PL and the minimum gradient length PL. For example, the variation between the minimum gradient length of 14 mm and the maximum gradient length of 18 mm can be linear, such as a minimum gradient length of 14 mm with a downlight value of 0.75 D and a maximum gradient length of 18 mm with a downlight value of 2.5 D.

[0041] According to other embodiments that can be considered individually or in combination, the downlight value is obtained from at least one of the following parameters:

[0042] -Add light according to the user's prescription,

[0043] -The user's average focal length for distance vision prescriptions.

[0044] -The user's average prescription focal length for near vision and the user's average prescription focal length for distance vision.

[0045] - User's age

[0046] -The user's average prescription focal length for distance vision and the user's age.

[0047] This avoids the need for opticians to perform additional measurements.

[0048] This disclosure further relates to a method for providing ophthalmic lens surface data via a computer device, the ophthalmic lens surface data being intended for use in the manufacture of ophthalmic lenses, the method comprising the following steps:

[0049] - Determine the gradient length PL of the ophthalmic lens as described in this instruction manual.

[0050] - Provide ophthalmic lens surface data by taking into account the determined gradient length.

[0051] According to an embodiment of a method for providing surface data of an ophthalmic lens implemented via a computer device, the gradient length is a virtual gradient length of the virtual ophthalmic lens. The virtual ophthalmic lens may be a target virtual lens.

[0052] In combination with the aforementioned method, the step of providing ophthalmic lens surface data by taking into account the determined gradient length PL includes the following steps:

[0053] Provide surface data S,

[0054] - By modifying the surface data S, modified surface data S' is provided so as to change at least the value of the near reference point NVP on the y-axis, such that:

[0055] - The distance between the value of the FC crosshair on the y-axis and the value of the NVP (near reference point) on the y-axis corresponds to the determined gradient length, and

[0056] - The average spherical and cylindrical lenses of the modified surface data S' at the distance reference point FVP and the average spherical and cylindrical lenses of the modified surface data S' at the near reference point NVP have a maximum difference of 0.05 D from the average spherical and cylindrical lenses of the surface data S at the distance reference point FVP and the average spherical and cylindrical lenses of the surface data S at the near reference point NVP, respectively.

[0057] Ophthalmic lens surface data are provided based on the modified surface data S'.

[0058] In combination with the foregoing embodiments, the method may include the step of providing surface data S, which includes the following steps:

[0059] - Provide 42 initial surface data Sini associated with a first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(Pl) and a cylindrical lens Cyl(Pl).

[0060] - Select 45 n modified surface data Smod1, ..., Smod i ... Smod n ,

[0061] n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n.

[0062] The modified surface data Smod1, ..., Smodi ... Smod n Associated with a second coordinate system, where n is a non-zero integer;

[0063] - Locate the n modified surface data Smod1, ..., Smod i ... Smod n (46)

[0064] During this period, the relative position and / or relative orientation of the first coordinate system with respect to the second coordinate system are determined, and

[0065] During this period, the n modified surface data Smod represented in the first coordinate system are S'mod1, ..., S'mod1, ..., S'modn.

[0066] - Combine 47 n modified surface data to determine surface data S as follows:

[0067] S = Sini +

[0068] α i These are non-zero weighting coefficients.

[0069] "Positioning" means rotating and / or translating the modified surface data.

[0070] Advantageously, by using modified surface data as described above, the position and / or extent of a region of the ophthalmic lens can be easily and locally modified. This region can be the near vision region, and / or the distance vision region, and / or the intermediate vision region. Thus, for example, greater visual comfort can be achieved by making it easier to access the near vision region while maintaining a comfortable size for the near vision region.

[0071] Alternatively or in combination with the foregoing methods, the step of providing surface data S includes the following steps:

[0072] - Provide 42 initial surface data Sini associated with a first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(Pl) and a cylindrical lens Cyl(Pl).

[0073] - Select n surface data modifiers Smod1, ..., Smod i ... Smod n ,

[0074] n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n.

[0075] The modified surface data Smod1, ..., Smod i ... Smodn Associated with the first coordinate system, where n is a non-zero integer;

[0076] - Combine n modified surface data such that surface data S is determined by the following:

[0077] S = Sini +

[0078] α i These are non-zero weighting coefficients.

[0079] Advantageously, by using modified surface data, as described above, with the same coordinate system as the initial surface data, the position and extent of the distant viewing area and / or the position and extent of the near viewing area can be easily and globally modified.

[0080] Alternatively or in combination with the aforementioned methods, the n weighting coefficients α in this step i It is calculated based on at least one of the following parameters:

[0081] -Prescription average focal density

[0082] -Prescription astigmatism

[0083] -Prescription with added light

[0084] - Subtraction of light based on the user's age.

[0085] This avoids the need for opticians to perform additional measurements.

[0086] Alternatively or in combination with the aforementioned methods, the surface data is modified to enlarge near vision, thereby increasing the accessibility of the near vision zone for new progressive lens wearers and thus enlarging the near vision zone.

[0087] Advantageously, according to this embodiment, progressive lenses can provide wearers with high visual comfort, particularly providing a wide field of vision and easy access to the near vision zone (without requiring excessive lowering of the eye's gaze direction to approximate an ergonomic posture), while also providing limitations on the degree of distortion caused by the progressive lens design (in particular, the resulting gradient of astigmatism).

[0088] Alternatively or in combination with the aforementioned methods, modifying the surface data is selected to expand the viewing area.

[0089] Another aspect of this disclosure relates to an ophthalmic lens computing device suitable for implementing the methods described herein.

[0090] Another aspect of this disclosure relates to an ophthalmic element comprising:

[0091] - An ophthalmic lens, which has at least the following characteristics:

[0092] The field of view region with a field of view reference point (FVP)

[0093] Near region with near reference point NVP,

[0094] The principal gradient meridian passes through at least the far-viewing reference point FVP and the near-viewing reference point NVP.

[0095] The portion of the main gradient meridian that crosses the distance viewing area defines the vertical axis.

[0096] Prescription FC (Cross-face)

[0097] The prism reference point serves as the origin of a reference frame with a vertical y-axis, which allows for the definition of a value on the y-axis for each point on the lens.

[0098] The gradient length PL corresponds to the difference between the value of the lens fitting cross FC on the y-axis and the value of the near reference point NVP on the y-axis.

[0099] -Ophthalmic lenses have a first average power value P1 at the distance reference point FVP and a second average power value P2 at the near reference point NVP.

[0100] - Ophthalmic lenses include an added power value Add corresponding to the difference between a first average power value P1 and a second average power value P2.

[0101] - The near vision region has a generated astigmatic width at the near reference point NVP, which is evaluated as follows: the astigmatic value at the near reference point NVP plus the generated astigmatic value less than 0.5 D.

[0102] The resulting astigmatism width corresponds to the higher of the first width W1 and the second width W2, which are defined as follows:

[0103]

[0104]

[0105] Wherein, 1 < a < 2, 0.2 < b < 0.4, 11 < c < 12, 3 < d < 4, 4 < e < 6, 1 < f < 2, and 18 < g < 22.

[0106] The astigmatic width produced at the near reference point NVP is defined as follows: the astigmatic value at the near reference point NVP plus the astigmatic value produced below 0.5 D. The produced astigmatic width can be expressed in degrees. Attached Figure Description

[0107] Embodiments of the invention will now be described by way of example only with reference to the following accompanying drawings, in which:

[0108] - Figure 1 It demonstrates the definition of certain parameters for progressive ophthalmic lenses, in particular, Figure 1 include: Figure 1 A, which schematically illustrates a progressive ophthalmic lens; and Figure 1 B shows the power gradient curve along the meridian of the progressive lens.

[0109] - Figure 2 A flowchart illustrating an embodiment of a method for determining the gradient length of an ophthalmic element according to an embodiment of the present disclosure is provided.

[0110] - Figure 3 A model relating the downlight value to the gradient length according to an embodiment of the present disclosure is shown.

[0111] - Figure 4 A flowchart illustrating an embodiment of a method for providing ophthalmic lens surface data according to an embodiment of the present disclosure, the ophthalmic lens surface data being intended for use in the manufacture of ophthalmic lenses.

[0112] - Figure 5 A spatial diagram of ophthalmic lens surface data according to embodiments of the present disclosure is shown.

[0113] - Figure 6 An example of an implementation of the method according to this disclosure is shown.

[0114] - Figure 7 This is a graphical representation of the residual astigmatism width according to an embodiment of the present disclosure.

[0115] The elements in the figures are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the figures may be enlarged relative to other elements to aid in understanding the embodiments of this disclosure. Detailed Implementation

[0116] Throughout this instruction manual, terms such as "top," "bottom," "horizontal," "vertical," "above," "below," or other terms indicating relative position are used. It should be understood that these terms should be interpreted in the context of lens wearing conditions, and when referring to surfaces, these terms should be understood with reference to the prism reference point P. PRP Or, in the case of lenses, these terms should be referenced to the dispensing cross. Prism reference point P PRP The definition of the eyeglasses cross is as follows.

[0117] In the context of this invention, the term "ophthalmic lens" refers to a progressive ophthalmic lens, and can also refer to a lens suitable for the wearer, a finished lens, a rough-edged lens, a semi-finished lens, or a spectacle lens. The expression "progressive lens" (or "progressive spectacle") should be understood to mean an ophthalmic lens with a progressively changing power for use in vision correction eyeglasses.

[0118] The user's eye can be the user's right eye, or the user's left eye, or the user's virtual right eye, or the user's virtual left eye, or the user's central eye.

[0119] In the context of this invention, "virtual eye" refers to a digital representation of the user's eye. This digital representation may be, for example, a point with three coordinates, such as the center of rotation of the eye, optionally with a prescription.

[0120] In the context of this invention, the user's central eye is a virtual eye that serves as a reference for the user's binocular visual system. This central eye is positioned by default at the center of rotation of the two eyes, but it can be positioned at other locations on the line segment connecting the centers of rotation of the two eyes, for example, depending on visual dominance.

[0121] According to other embodiments that may be considered individually or in combination, the ophthalmic lens may be a real ophthalmic lens or a virtual ophthalmic lens intended to be worn in front of a user's virtual eyes. In the context of this invention, "virtual ophthalmic lens" means a digital representation of an ophthalmic lens (in spatial and / or optical / surface power).

[0122] The term "prescription value" or "prescription" is known in the art. It refers to one or more data points obtained for the wearer and indicating for each eye the following: prescription distance power, and / or prescription astigmatism value, and / or prescription astigmatism axis, and / or prescription additional power suitable for correcting refractive errors and / or presbyopia in each eye. The average distance power (PFV) is obtained by summing half of the prescription astigmatism value with the prescription average distance power value. Then, the average near power (PNV) for each eye is obtained by summing the prescription additional power value (A) with the prescription average distance power value for the same eye: PNV = PFV + A. In the case of progressive lens prescriptions, the prescription data includes wearer data that indicates at least the prescription distance power and prescription additional power value for each eye.

[0123] Surface quantities are expressed relative to points. These points lie in a reference system in which the origin is typically the prism reference point (PRP). Each point on the lens surface (front or back surface) is associated with an average spherical and cylindrical lens, which depend on the lens's refractive index. Lens manufacturers are required to indicate the location of the prism reference point (PRP) so that any optician can measure the lens's prism value. For progressive lenses, the prism reference point typically corresponds to the center of a micro-engraving on the lens. In this case, the lens manufacturer is also required to mark this micro-engraving.

[0124] Left side Figure 1 A schematic diagram illustrates a progressive ophthalmic lens. The term "progressive lens" (or "progressive glasses") should be understood as referring to an ophthalmic lens used for vision correction with a progressively changing power. A progressive lens includes a distance vision zone (FV) in its upper portion (the power of which is adapted to the wearer's distance vision based on their visual correction needs) and a near vision zone (NV) in its lower portion (the power of which is adapted to the wearer's near vision). Typically, as... Figure 1 As shown, the prism reference point PRP is the origin of a reference system. The x-axis of this reference system is parallel to the horizontal axis of the micro-engraving ME, the y-axis is vertical and perpendicular to the x-axis, and the z-axis (not shown) of this reference system is normal to the front surface at the prism reference point PRP. This reference system allows each point on the lens to be defined.

[0125] The standard ISO 13666:2012 defines certain parameters for fitting progressive lenses. Therefore, the reference point FVP is the manufacturer-defined distance vision point, for example, at the center of the circle defining the distance vision area. Similarly, the reference point NVP is the manufacturer-defined near vision point, for example, at the center of the circle defining the near vision area. The fitting cross (FC) is a point located on the front surface of the eyeglasses or semi-finished eyeglasses, which the manufacturer considers a reference point for positioning the eyeglasses in front of the eye. The fitting cross (FC) is generally marked with an erasable mark that is removed after fitting.

[0126] The gradient length PL is defined as the vertical distance between the lens cross and the near reference point NVP, and is usually expressed in mm.

[0127] In addition, the lens’s inner offset I (or inner displacement) is defined as the horizontal offset between the distance reference point FVP and the near reference point NVP.

[0128] The optical power of the lens preferably varies continuously between the distance reference point FVP and the near reference point NVP, along a line called the meridian M that passes through these two points. This meridian passes through at least the distance and near vision regions in the overall vertical direction.

[0129] The added power is defined as the difference between the average power at the distance reference point and the average power at the near reference point, and is usually expressed in diopters. The average power at the distance and near reference points can be obtained from measurements / prescriptions of the wearer, or from measurements of the lens at the distance reference point (FVP) and near reference point (NVP) using, for example, a focimeter. The average power at the near reference point may also be obtained from a fixed value based on the user's type, such as taking into account the user's age, rather than from measurements.

[0130] Figure 1 B shows a graph illustrating an example of the power gradient curve along the meridian of a progressive lens. The X-axis of the graph is the added power in diopters, and the Y-axis is the coordinate along the meridian in mm. At 8 mm, the added power value for the distance reference point FVP is shown as 0, and at -14 mm, the added power value for the near reference point NVP is shown as 2 D.

[0131] Figure 2 A flowchart illustrating an embodiment of a method for determining the gradient length of an ophthalmic element according to an embodiment of the present disclosure is provided. As previously explained, the ophthalmic lens may have a first average power value P1 at a distance reference point (FVP) and a second average power value P2 at a near reference point (NVP). The method according to the present disclosure may include the following steps:

[0132] - Provides the additional light value Add(21).

[0133] - Provides a model (22) that associates the downlight value Add with the gradient length (LP),

[0134] -Based on the model and the provided downlight value, determine the gradient length (23).

[0135] According to a preferred embodiment, the gradient length PL can be increased with the added light value. In this case, advantageously, even with a high added light value, the transition between the distance and near vision regions remains comfortable.

[0136] The subtractive power can be provided as a prescription, particularly the prescription subtractive power, or the prescription mean focal distance power and / or the prescription mean focal near power. Alternatively or in combination, the subtractive power can be estimated based on the user's age. Alternatively or in combination, the subtractive power can be estimated based on the user's age and the focal distance reference point (FVP). The relationship between subtractive power and user age can be obtained statistically by collecting data from many users, or theoretically, as explained in the following article: Anderson et al. Minus-Lens–Stimulated Accommodative Amplitude Decreases Sigmoidally with Age: A Study of Objectively Measured Accommodative Amplitudes from Age 3, 2008, Invest Ophthalmol Vis Sci., July 2008; 49(7): 2919-2926.

[0137] The model can be limited by the maximum gradient length LP and the minimum gradient length LP, for example, between 7 mm and 22 mm, between 12 mm and 20 mm, and preferably between 14 mm and 18 mm.

[0138] The model can use different kinds of relationships between the added light value and the gradient length, such as linear, parabolic, or exponential changes.

[0139] The model can be prescription-dependent. For example, the model can vary depending on the type of refractive error and / or presbyopia in each of the wearer's eyes.

[0140] The model can be determined by the amount of light added, the spherical lens (average spherical lens or binocular average spherical lens) or cylindrical lens, or the user's age.

[0141] The model can correlate the added light value (Add) of an ophthalmic lens with the gradient length (LP) of the same lens.

[0142] Models can be obtained from wearer measurements, theoretical models, simulated wearer measurements, and statistical databases. Models can also utilize machine learning, such as neural networks.

[0143] The model's input is either the added power value or the added power value and the distance vision. If not specified, the added power value can be estimated based on the prescribed values ​​(e.g., the prescription average distance vision power and the prescription average near vision power) or the wearer's age.

[0144] Once input is provided to the model, an output is obtained, which is a gradient of length. In other words, the gradient length is determined based on the model and the provided underlight values.

[0145] According to other embodiments that may be considered individually or in combination, the gradient length (LP) is the virtual gradient length of the virtual ophthalmic lens.

[0146] According to other embodiments that can be considered individually or in combination,

[0147] The model includes a first sub-model and a second sub-model, and

[0148] The steps to determine the virtual gradient length include:

[0149] - Provides a first sub-model that associates the downlight value Add with a reduction in the gaze angle.

[0150] -Based on the first sub-model and the provided additional light value, determine the reduction in gaze angle.

[0151] - Provide a second sub-model that correlates the reduced gaze angle with the virtual gradient length.

[0152] - Determine the virtual gradient length (LP) based on the second sub-model and reduced gaze angle.

[0153] The concept of “gazing at a lower angle” is known to those skilled in the art, and is explained in particular in the referenced patent document WO2015 / 074777 A1.

[0154] For example, statistical databases can be obtained from measurements of the reduced gaze angle of a group of users while these users are reading on smartphones or tablets, as described in applications EP 3361929 or EP 3362845.

[0155] For example, a group can have more than 100 users, more than 1,000 users, more than 10,000 users, more than 100,000 users, or more than 200,000 users.

[0156] Each user's prescription (e.g., under-illuminated, and / or spherical / average spherical / binocular average spherical) can be correlated with that user's measured angle of reduced gaze.

[0157] Based on all this collected information, a first sub-model can be obtained regarding the relationship between the gaze reduction angle (or average gaze reduction angle), spherical power (or average spherical power or binocular average spherical power), and the added refraction, for example...

[0158] The angle of reduced gaze = A * spherical lens + B * additional light + C

[0159] For example: 0.1 < A < 0.2, 0.4 < B < 0.6, and 24 < C < 26.

[0160] Alternatively, the first sub-model between the gaze reduction angle and the downlight could be, for example...

[0161] Gaze angle reduction = B' * under-lighting + C'

[0162] The first sub-model can be linear or non-linear.

[0163] Then, based on the gaze reduction angle, the virtual gradient length can be determined based on the second sub-model, for example as described below.

[0164] The second sub-model can be linear or non-linear.

[0165] Optionally, the second sub-model may include modulating the virtual gradient length through a transmission law (linear or nonlinear) to obtain the determined virtual gradient length. Figure 3 A model relating the add-on light value to the virtual gradient length is shown. In the figure, the model is represented graphically, with the add-on light value Add (D) on the x-axis and the virtual gradient length PL (mm) on the y-axis. In this example, the relationship between the add-on light value and the virtual gradient length is linear and limited to between LP1 = 14 mm and LP2 = 18 mm, corresponding to add-on light values ​​Add1 = 0.75 D and Add2 = 2.5 D. When the add-on light is less than 0.75 D, the model is constant, and the virtual gradient length equals LP1; when the add-on light is greater than 2.5 D, the model is constant, and the virtual gradient length equals LP2.

[0166] According to another embodiment, which can be considered individually or in combination, the eye is the central eye. In this embodiment, the ophthalmic lens worn in front of the user's central eye is a virtual ophthalmic lens. In this embodiment, if the downlighting for both eyes is the same, then the provided downlighting is identical; if the downlighting for both eyes is different, then the provided downlighting can be the average downlighting between the two eyes, the weighted downlighting between the two eyes, the minimum downlighting, or the maximum downlighting. Therefore, the determined length gradient is a virtual length gradient of the virtual ophthalmic lens in front of the central eye.

[0167] Advantageously, this embodiment allows for a common reference between the two eyes and can improve the binocular performance of an ophthalmic lens by taking into account the central eye.

[0168] Figure 4 A flowchart illustrating an embodiment of a method for providing surface data of an ophthalmic lens, implemented via a computer device, the ophthalmic lens surface data being intended for use in the manufacture of ophthalmic lenses, the method comprising the following steps:

[0169] - Based on steps 21, 22, and 23 described previously, determine the virtual gradient length PL of the ophthalmic element, and

[0170] - Provides 41 virtual ophthalmic lens surface data by taking into account the determined gradient length.

[0171] Ophthalmic lens surface data can be obtained by directly executing the determined virtual gradient length.

[0172] Alternatively, ophthalmic lens surface data can be obtained indirectly using surface data, which the method will begin with, as explained below.

[0173] Therefore, the step of providing 41 virtual ophthalmic lens surface data by taking into account the determined virtual gradient length may include the following steps:

[0174] - Provides 42 surface data points.

[0175] - Modified surface data S' is provided by modifying surface data S of surface 43 to change at least the value of the near reference point NVP on the y-axis, such that:

[0176] - The distance between the value of the FC crosshair on the y-axis and the value of the NVP (near reference point) on the y-axis corresponds to the determined virtual gradient length, and

[0177] - The average spherical and cylindrical lenses of the modified surface data S' at the distance reference point FVP and the average spherical and cylindrical lenses of the modified surface data S' at the near reference point NVP have a maximum difference of 0.05 D from the average spherical and cylindrical lenses of the surface data S at the distance reference point FVP and the average spherical and cylindrical lenses of the surface data S at the near reference point NVP, respectively.

[0178] - Provides 44 virtual ophthalmic lens surface data based on the modified surface data S'.

[0179] To manufacture ophthalmic lenses, the back and / or front of the lens are machined based on “virtual” lens data (hereinafter referred to as “ophthalmic lens surface data”), which is optimized to simultaneously possess desired design characteristics determined for the wearer based on the added optical value and the refractive error correction prescribed for that wearer. In known methods, this optimization is performed digitally starting from a target virtual lens (hereinafter referred to as “surface data” or, hereinafter, “initial surface data”), in a manner that yields the distribution of optical quantities such as power and astigmatism. Procedures designed to perform such optimizations are considered known to those skilled in the art and are not described herein.

[0180] According to an embodiment of a method for providing surface data of an ophthalmic lens implemented via a computer device, the gradient length is a virtual gradient length of the virtual ophthalmic lens. The virtual ophthalmic lens can be a target virtual lens. The surface data S includes a plurality of surface points PI, each surface point PI having an average spherical lens power Sph(Pl) and a cylindrical lens power Cyl(Pl). The surface data S has a refractive function. The origin of the first coordinate system is preferably located at the middle of the micro-engraved ME, such as... Figure 1 As shown in A.

[0181] According to an embodiment of a method for providing surface data of an ophthalmic lens implemented via a computer device, the gradient length is a virtual gradient length of the virtual ophthalmic lens. The virtual ophthalmic lens may be a target virtual lens.

[0182] For example, ophthalmic lens surface data can be determined based on the methods described in this application.

[0183] For example, ophthalmic lens surface data can be determined based on the methods described in this application.

[0184] Figure 5 The steps for modifying surface data S of 43 are shown in the figure. Figure 5 An example spatial diagram of ophthalmic lens surface data with a near reference point NVP1 and a first gradient length LP1 is shown. The first gradient length is defined as the distance between the value of the fitting crosshair FC on the y-axis and the value of the near reference point NVP1 on the y-axis. The value of the near reference point NVP1 on the x-axis corresponds to an inward shift I1. The gradient length LP2 is determined according to steps 21, 22, and 23 described previously, and the ophthalmic lens surface data is modified to at least change the value of the near reference point NVP on the y-axis such that the distance between the value of the fitting crosshair FC on the y-axis and the modified value of the near reference point NVP2 on the y-axis corresponds to the determined gradient length LP2.

[0185] like Figure 5As shown, the x and y positions of the near reference point NVP change as the gradient length changes, thus the inward shift can also change. Therefore, the value of the near reference point NVP2 on the x-axis can correspond to the inward shift I2.

[0186] In step 43, the surface data S is further modified to at least change the value of the near reference point NVP on the y-axis, such that the average spherical and cylindrical lenses of the modified surface data at the far reference point FVP, and the average spherical and cylindrical lenses of the modified surface data at the near reference point NVP, are respectively close to the average spherical and cylindrical lenses of the surface data S at the far reference point FVP, and the average spherical and cylindrical lenses of the surface data S at the near reference point NVP, respectively. "Close to" means that the maximum difference between the average spherical and cylindrical lenses of the modified surface data at the far reference point FVP, and the average spherical and cylindrical lenses of the modified surface data at the near reference point NVP, and the average spherical and cylindrical lenses of the surface data S at the far reference point FVP, and the average spherical and cylindrical lenses of the surface data S at the near reference point NVP, respectively, is 0.05 D.

[0187] To satisfy these two conditions, the surface data needs to be modified. Several known methods exist that can be used individually or in combination.

[0188] For example, to apply to surface data, a shear function as described in application US 2010079722 can be used. In this application, the principle of the shear function should be understood as a translation of the optical properties of the lens relative to a fixed coordinate system associated with the lens, the magnitude of which varies along a direction perpendicular to the translation direction.

[0189] For example, to apply to surface data, a scaling function as described in application US 2010004593 can be used.

[0190] Alternatively, any other function, scaling function, or shearing function that satisfies the above two conditions is known to those skilled in the art.

[0191] According to one embodiment of this disclosure, such as Figure 4 As shown, the method may include the step of providing surface data S, which includes the following steps:

[0192] - Provide initial surface data Sini associated with the first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(Pl) and a cylindrical lens Cyl(Pl).

[0193] - Select 45 n modified surface data Smod1, ..., Smod i ... Smod n ,

[0194] n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n.

[0195] The modified surface data Smod1, ..., Smod i ... Smod n Associated with a second coordinate system, where n is a non-zero integer;

[0196] - Locate the 46 n modified surface data Smod1, ..., Smod i ... Smod n 46,

[0197] During this period, the relative position and / or relative orientation of the first coordinate system with respect to the second coordinate system are determined, and

[0198] During this period, the n modified surface data Smod represented in the first coordinate system are S'mod1, ..., S'mod1, ..., S'modn.

[0199] - Combine 47 n modified surface data to determine surface data S as follows:

[0200] S = Sini +

[0201] α i These are non-zero weighting coefficients.

[0202] "Positioning" means rotating and / or translating the modified surface data.

[0203] Alternatively or in combination with the foregoing methods, the step of providing surface data S includes the following steps:

[0204] - Provide initial surface data Sini associated with the first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(Pl) and a cylindrical lens Cyl(Pl).

[0205] - Select 45 n modified surface data Smod1, ..., Smod i ... Smod n ,

[0206] n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n.

[0207] The modified surface data Smod1, ..., Smod i ... Smod n Associated with the first coordinate system, where n is a non-zero integer;

[0208] - Combine 47 n modified surface data to determine surface data S as follows:

[0209] S = Sini +

[0210] α i These are non-zero weighting coefficients.

[0211] Advantageously, by using modified surface data, as described above, with the same coordinate system as the initial surface data, the position and extent of the distant viewing area and / or the position and extent of the near viewing area can be easily and globally modified.

[0212] During surface data provision step 45, an initial surface Sini associated with a first coordinate system is provided. The initial surface Sini comprises multiple surface points PI, each surface point PI having an average spherical lens Sph(Pl) and a cylindrical lens Cyl(Pl). The initial surface Sini has an initial refractive function. The origin of the first coordinate system is preferably located at the center of the micro-engraved ME, such as... Figure 1 As shown in A.

[0213] Each modified surface data Smodi can include multiple surface points Pi1, ..., Pij, ..., Pim.

[0214] Each surface point Pij has an average spherical mirror Sph(Pij) and a cylindrical mirror Cyl(Pij).

[0215] n, i, j are integers, where n ≥ 1, 1 ≤ i ≤ n, 1 ≤ j ≤ m, and m ≥ 1.

[0216] The selection step could be, for example, directly providing modified surface data.

[0217] The selection step can also be, for example, a calculation step, in which the surface data is modified by optimization to achieve the following:

[0218] At least one surface point or a line-of-sight direction is selected (preferably a set of line-of-sight surface points or directions, thereby sampling the entire field of vision). The current optical performance of each selected location (e.g., the near vision region) is evaluated, including at least the average focal power and the resulting astigmatism (as defined later). Based on these current optical performances, a set of modified surface data is created by modifying the initial surface data around the selected surface point or direction. This modification is accomplished by attenuating the performance gap (e.g., the gap in resulting astigmatism) between the current direction / point and the direction / point at the same reduced direction / height on the optical / surface meridian of the ophthalmic lens.

[0219] The attenuation can be evaluated, for example, by defining a Gaussian function (e.g., exp(-x² / sigmaX²)) that differs from the horizontal and vertical standard deviations (sigmaX and sigmaY), or by defining a trigonometric function (e.g., atan(x)) or, for example, a combination of different functions. Preferably, sigmaX can be fixed based on an initial width that is a relative change of 0.5 D in the resulting astigmatism.

[0220] n modified surface data Smod1, ..., Smod i ... Smod n It can be associated with either the first or the second coordinate system.

[0221] In the case of a first coordinate system and a second coordinate system, during positioning step 46, the relative position and relative orientation of the first and second coordinate systems are determined. "Positioning" means rotating and / or translating the modified surface data. Position and orientation can be accomplished by positioning and orienting one of the first and second coordinate systems in the other. For example, positioning and orienting the first coordinate system in the second coordinate system, and vice versa. Therefore, the relative position and / or relative orientation of the first coordinate system relative to the second coordinate system is determined, and the n modified surface data Smod represented in the first coordinate system are S'mod1, ..., S'modi, ..., S'modn.

[0222] If the coordinate system of the modified surface data and the initial surface data is the same, the positioning step may not be necessary.

[0223] During the combination step 47, the n modified surfaces are combined according to the following expression to obtain functionalized ophthalmic lens surface data:

[0224] S = Sini + Or S = Sini +

[0225] α i These are non-zero weighting coefficients.

[0226] Advantageously, the refractive function of the modified initial surface is modulated by combining at least one selected modified surface, based on the refractive function of the at least one selected modified surface.

[0227] During positioning step 46, the combination can link the first and second coordinate systems by performing the main axis along which the light is applied and the correspondence between at least the points in the first coordinate system and the points in the second coordinate system.

[0228] The method of the present invention may further include a weighting coefficient determination step prior to the combination step, during which the value of a weighting coefficient α is determined / calculated based on wearer parameters of the ophthalmic lens (e.g., based on the wearer's prescription, prescription mean power, prescription astigmatism, prescription additional power, or additional power derived from the user's age). For example, the weighting coefficient α can be evaluated using a function of the wearer's prescription, a × Add + b, where a and b are coefficients dependent on the wearer's prescription (prescription power, prescription astigmatism), which are evaluated, for example, by a function or selected within a subdivision range (i.e., a predetermined range of power and astigmatism is associated with a given value of a and b).

[0229] According to one embodiment, modifying surface data is selected as modifying a region of the ophthalmic lens.

[0230] In a preferred embodiment, modifying the surface data is selected to expand the near-field region.

[0231] Furthermore, to improve near vision accessibility for new progressive lens wearers, the near vision zone can be enlarged by modifying the ophthalmic lens surface data to reduce (unnecessary) astigmatism generated on each side of the near point. This enlargement must preserve the original lens power variation.

[0232] The resulting astigmatism is defined as the difference between the prescription astigmatism and the astigmatism generated by the working lens in a reference frame associated with the eye for each gaze direction. The resulting astigmatism may also be referred to as residual astigmatism.

[0233] "Enlarging the near field of view" means estimating the required magnification by simulating the width of a target or planar object located at a near task distance (e.g., 40 cm) and calculating the resulting astigmatism value under these conditions. Therefore, the width at which the resulting astigmatism value is below a given value (e.g., 0.5 D) corresponds to the required magnification. The target width can be determined using a current digital object such as a smartphone, tablet, keyboard, or A4 paper.

[0234] This magnification can be achieved in the following two ways:

[0235] - By adding weighted, modified surface data, the cylinder of the initial surface data on each side of the near point is reduced. This weighted, modified surface data will primarily modify the initial surface data in the near vision zone. However, reducing the cylinder does not always mean reducing residual astigmatism, especially in the near vision zone where the prismatic effect is high.

[0236] - Using weighted, modified surface data obtained through an optimization process, astigmatism generated in the gaze direction on each side of the near reference gaze is reduced. This weighted, modified surface data will primarily modify the initial surface data in the near vision zone. Advantageously, modifying the surface data will affect the initial surface data. Therefore, modifying the surface will slightly distort the initial surface data. In practice, this means that the modification to the initial surface data is limited to a small portion of the initial surface data, while the rest remains unchanged.

[0237] Therefore, this method proposes to provide and combine n modified surface data in order to customize the optical function of ophthalmic lenses.

[0238] Each modification to surface data, or a specific combination of surface modifications, allows for the addition of specific optical functions to the initial optical functions.

[0239] The method according to the present invention can be implemented as follows:

[0240] - From the lens designer's perspective, during the optimization process of optical lenses, or

[0241] - On the lens manufacturer's side, for example, by modifying manufacturing data.

[0242] Advantageously, the method according to the invention allows:

[0243] - Saves time when customizing designs, as only a few surface modifications need to be optimized.

[0244] - The flexibility of customization and subdivision becomes a practical option in laboratory calculations; in fact, the method according to the invention allows for the simple addition of modified surfaces to the initial surface.

[0245] For example, the inventors have developed a modified surface data that is applied to the initial surface data of the surface of an ophthalmic lens (e.g., the frontal surface) to widen the near vision zone, but without modifying the remaining mean spherical and cylindrical lens distributions.

[0246] Figure 6 An example of an implementation of this disclosure is shown, in particular an astigmatic diagram. Such a diagram, i.e., an astigmatic diagram, is well known.

[0247] Figure 6 The contour lines for a 0.5 D residual astigmatic cylinder are shown. Dashed line I represents the initial surface data. Solid line II represents the ophthalmic lens surface data derived from the modified initial surface data. Figure 6 It shows an expansion of the near vision zone, with the width of the field of vision increasing by nearly 30% in the gaze direction corresponding to the near vision reference point.

[0248] According to another embodiment, to achieve a good trade-off between near vision entry and near vision zone width, the gradient length can be maintained depending on the added optical value, and the gradient length can be customized according to the wearer's preference for near vision entry and near vision zone width. For example, different gradient lengths PL1 and PL2 can be offered to the wearer, where PL1 > PL2 (the near vision entry of an ophthalmic lens with a gradient length PL2 is better than that of an ophthalmic lens with a gradient length PL1), and different near vision zone widths NVwidth1 and NVwidth2 can be offered to the wearer, where NVwidth1 > NVwidth2 (the near vision zone width NVwidth1 is more comfortable than the near vision zone width NVwidth2). In practice, using a longer gradient length allows for a larger near vision zone width. Therefore, the user will express his / her preference between the pair PL1, NVwidth1 and PL2, NVwidth2.

[0249] According to one embodiment of this disclosure, such as Figure 4 As shown, the initial surface data Sini can be modified to at least change the value of the near reference point NVP on the y-axis, such that:

[0250] - The distance between the value of the FC crosshair on the y-axis and the value of the NVP (near reference point) on the y-axis corresponds to the determined gradient length, and

[0251] - The average spherical and cylindrical lenses of the modified initial surface data at the distance reference point FVP and the average spherical and cylindrical lenses of the modified initial surface data at the near reference point NVP have a maximum difference of 0.05 D from the average spherical and cylindrical lenses of the initial surface data at the distance reference point FVP and the average spherical and cylindrical lenses of the initial surface data at the near reference point NVP, respectively.

[0252] In this case, prior to the combination step 47, the initial surface data is modified by taking into account the determined gradient length.

[0253] This disclosure also relates to an ophthalmic lens computing device suitable for implementing the method according to this specification, the ophthalmic lens computing device comprising:

[0254] - An order request receiving device adapted to receive ophthalmic lens order requests that include at least the wearer's ophthalmic prescription.

[0255] - An initial surface data determining device adapted to determine the initial surface data Sini and relative position of an ophthalmic lens based on an order request.

[0256] - A surface data providing device adapted to provide at least one modified surface data Smodi and at least one non-zero weighting coefficient α.

[0257] - A computing device adapted to combine at least one modified surface Smod.

[0258] The ophthalmic lens computing device according to this disclosure may further include a communication device adapted to communicate with at least one remote entity to provide a modified surface Smod and / or the corresponding weighting coefficient α.

[0259] According to another aspect, this disclosure relates to a computer program product comprising one or more stored instruction sequences accessible to a processor, and

[0260] The one or more stored instruction sequences, when executed by the processor, cause the processor to perform the steps of the method according to this specification.

[0261] According to another aspect, this disclosure relates to an ophthalmic element intended to be worn in front of a user's eye, the ophthalmic element comprising:

[0262] - An ophthalmic lens, which has at least the following characteristics:

[0263] The field of view region with a field of view reference point (FVP)

[0264] Near region with near reference point NVP,

[0265] A principal gradient meridian passing through at least the distance reference point FVP and the near reference point NVP, the portion of which passes through the distance region, defines the vertical axis.

[0266] Prescription FC (Cross-face)

[0267] The prism reference point serves as the origin of a reference frame with a y-axis, which allows for the definition of a y-axis value relative to the vertical axis for each point on the lens.

[0268] The gradient length PL corresponds to the difference between the value of the lens fitting cross FC on the y-axis and the value of the near reference point NVP on the y-axis.

[0269] -Ophthalmic lenses have a first average power value P1 at the distance reference point FVP and a second average power value P2 at the near reference point NVP.

[0270] The ophthalmic lens includes an added power value Add corresponding to the difference between a first average power value P1 and a second average power value P2.

[0271] The near-vision region has the resulting astigmatic width at the near-vision reference point NVP.

[0272] The resulting astigmatism width corresponds to the higher of the first width W1 and the second width W2, which are defined as follows:

[0273]

[0274]

[0275] Wherein, 1 < a < 2, 0.2 < b < 0.4, 11 < c < 12, 3 < d < 4, 4 < e < 6, 1 < f < 2, and 18 < g < 22.

[0276] The astigmatic width produced at the near reference point NVP is defined as follows: the astigmatic value at the near reference point NVP plus the astigmatic value produced below 0.5 D. The produced astigmatic width can be expressed in degrees.

[0277] Figure 7 This is a graphical representation of the residual astigmatism width as a function of the applied light according to embodiments of the present disclosure. Curve 61 represents the variation of the residual astigmatism width of the ophthalmic lens according to the present disclosure with the applied light. Curves 62 and 63 are fits to curve 61; specifically, curve 62 fits curve 61 before 1.5 D, and curve 63 fits curve 61 after 1.5 D. Curves 62 and 63 can be simulated according to equations W1 and W2, respectively.

[0278] The advantages presented by the ophthalmic lens according to this disclosure are that it provides a progressive lens that offers the wearer high visual comfort, particularly a wide field of vision for near vision and easy access to the near vision zone (without requiring excessive lowering of the eye's gaze direction to approximate an ergonomic posture), while also providing limitation on the degree of distortion caused by the PAL design (in particular, an undesirable gradient of astigmatism).

[0279] Many other modifications and variations will arise in those skilled in the art when referring to the foregoing illustrative embodiments. These illustrative embodiments are given by way of example only and are not intended to limit the scope of the invention, which is defined only by the appended claims.

[0280] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a / an" does not exclude a plurality / types. The simple fact that different features are described in mutually different dependent claims does not indicate that combinations of these features cannot be advantageously used. No reference numerals in the claims should be construed as limiting the scope of the invention as defined in a set of claims.

Claims

1. A method implemented via a computer device for determining a virtual progressive length (LP) of a virtual ophthalmic lens intended to be worn in front of a central eye, the central eye being a virtual eye used as a reference for a user's binocular visual system, the virtual eye being a digital representation of the user's eye, the virtual ophthalmic lens being a digital representation of an ophthalmic lens, each of the user's eyes having a center of rotation, the virtual eye being positioned on a line segment connecting the centers of rotation of the user's two eyes, the virtual ophthalmic lens being a virtual progressive spectacle lens, the method comprising the steps of: - Provides the downlight value Add(21) for each eye. - Determine the virtual downlight value of the central eye, which is the average downlight value between the two downlight values ​​of the user's two eyes. - Provide a model (22) that associates the virtual under-illuminated value with the virtual gradient length (LP). -Based on the model and the determined virtual under-illuminated value, the virtual gradient length is determined (23).

2. The method according to claim 1, wherein, The model includes a first sub-model and a second sub-model, and The first sub-model associates the added light value (Add) with a reduction in the gaze angle. The second sub-model links the reduction in gaze angle to the virtual gradient length, and in which, The steps for determining the virtual gradient length include: - Based on the first sub-model and the provided downlight value, determine the reduction in gaze angle. - Based on the second sub-model and the reduced gaze angle, the virtual gradient length (LP) is determined.

3. The method according to claim 1 or 2, wherein, The model is based on the user's prescription.

4. The method according to claim 1 or 2, wherein, The model is based on a statistical database.

5. The method according to claim 1 or 2, wherein, The downlight value is obtained from at least one of the following parameters: -The user's prescription includes light. -The user's average prescription focal length for near vision and the user's average prescription focal length for distance vision. -The age of the user, - The user's average prescription focal length for distance vision and the user's age.

6. A method implemented via a computer device for providing surface data of a virtual ophthalmic lens, the surface data of which is intended for use in manufacturing ophthalmic lenses, the method comprising the steps of: - Determine the virtual gradient length PL of the virtual ophthalmic lens according to any one of claims 1-5. - The surface data of the virtual ophthalmic lens (41) is provided by taking into account the determined virtual gradient length.

7. The method according to claim 6, wherein, The virtual ophthalmic lens is defined as having at least the following characteristics: The distance viewing area with a distance reference point (FVP) Near region with near reference point (NVP), A principal gradient meridian passing through at least the far vision reference point (FVP) and the near vision reference point (NVP), the portion of the principal gradient meridian passing through the far vision region, defines a vertical axis. FC (Front-Cut) The prism reference point serves as the origin of a reference frame with a y-axis, which allows for defining a value on the y-axis relative to the vertical axis for each point on the virtual ophthalmic lens. The virtual gradient length (LP) corresponds to the difference between the value of the fitting cross (FC) on the y-axis and the value of the near reference point (NVP) on the y-axis. The step of providing the surface data of the virtual ophthalmic lens (41) by taking into account the determined virtual gradient length includes the following steps: - Provide surface data S (42), - By modifying the surface data S (43) to provide modified surface data S', at least the value of the near reference point NVP on the y-axis is changed, such that: - The distance between the value of the fitting crosshair (FC) on the y-axis and the value of the near reference point (NVP) on the y-axis corresponds to the determined virtual gradient length, and The modified surface data S' has a maximum difference of 0.05 D between its average spherical and cylindrical refractive power at the far vision reference point (FVP) and its average spherical and cylindrical refractive power at the near vision reference point (NVP) and its average spherical and cylindrical refractive power at the far vision reference point (FVP) and its average spherical and cylindrical refractive power at the near vision reference point (NVP), respectively. - Provide the surface data of the virtual ophthalmic lens according to the modified surface data S' (44).

8. The method according to claim 7, wherein, The steps for providing surface data S include the following: - Provide (45) initial surface data Sini associated with a first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(PI) and a cylindrical lens Cyl(PI), - Select (45)n modified surface data Smod1, ..., Smod i ... Smod n , n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n. The modified surface data Smod1, ..., Smod i ... Smod n Associated with a second coordinate system, where n is a non-zero integer; - Locate the n modified surface data Smod1, ..., Smod i ... Smod n (46) During this period, the relative position and / or relative orientation of the first coordinate system with respect to the second coordinate system are determined, and during this period, the n modified surface data Smod represented in the first coordinate system are S'mod1, ..., S'mod1, ..., S'modn. - Combine (47) the n modified surface data such that the surface data S is determined by the following: S = Here + α i These are non-zero weighting coefficients.

9. The method according to claim 7, wherein, The steps for providing surface data S include the following: - Provide (45) initial surface data Sini associated with a first coordinate system, the initial surface data Sini comprising a plurality of surface points PI, each surface point PI having an average spherical lens Sph(PI) and a cylindrical lens Cyl(PI), - Select (45)n modified surface data Smod1, ..., Smod i ... Smod n , n and i are integers, where n ≥ 1 and 1 ≤ i ≤ n. The modified surface data Smod1, ..., Smod i ... Smod n Associated with the first coordinate system, where n is a non-zero integer; - Combine (47) the n modified surface data such that the surface data S is determined by the following: S = Here + α i These are non-zero weighting coefficients.

10. The method according to claim 8 or 9, wherein, The n weighting coefficients α i It is calculated based on at least one of the following parameters: -Prescription average focal density -Prescription astigmatism -Prescription with added light - The downlight is based on the user's age.

11. The method according to claim 8 or 9, wherein, The modified surface data is selected to expand the near-viewing region and / or the far-viewing region.

12. An ophthalmic lens computing device, said ophthalmic lens computing device being adapted to implement the method according to any one of claims 1 to 11.

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