Method for determining an ophthalmic lens and associated optometry device

Abstract

The invention relates to a method for determining an ophthalmic lens intended to be worn by an individual, said ophthalmic lens being adapted to provide a visual correction to the individual in at least one given visual gaze direction, said visual correction being based on wearer data comprising prescription data of the individual, wherein the method comprises the steps of: - determining a parameter related to the accommodation dynamics of the eye of the individual, - determining said ophthalmic lens based on said wearer data and the parameter related to the accommodation dynamics of the eye of the individual. The invention also relates to a device for determining a parameter related to the accommodation dynamics of the eye of an individual in a method according to the invention.

Description

Technical Field

[0001] This invention relates to the field of optometry and the field of determining ophthalmic lenses suitable for switching from distance vision to near vision (and vice versa).

[0002] More precisely, the present invention relates to a method for determining ophthalmic lenses intended to be worn in front of an individual's eyes.

[0003] The present invention also relates to an optometric device for determining parameters used in the above methods. Background Technology

[0004] Recent advancements in digital products (such as smartphones or tablets) have increased the engagement of our visual and attentional systems. Commercial ophthalmic lenses now exist that help wearers better manage this intense near-vision demand, thanks to an enhancement in the lower half of the lens. This enhancement is designed to reduce accommodative effort when switching from distance to near vision.

[0005] Within this objective, there are products specifically designed for certain age groups. In fact, this accommodative effort is related to the maximum accommodative amplitude. Compared to newly emerging presbyopia, younger people with higher accommodative amplitudes can more easily maintain near-vision effort for extended periods.

[0006] However, even within the same age group, regulatory dynamics differ among individuals. For example, there is individual variability in the magnitude of regulatory responses within the same age group. Summary of the Invention

[0007] Therefore, one object of the present invention is to provide a method for determining an ophthalmic lens suitable for all individuals when all individuals switch from distance vision to near vision (or vice versa).

[0008] According to the present invention, the above objective is achieved by a method for determining an ophthalmic lens intended for an individual to wear, the ophthalmic lens being adapted to provide visual correction to the individual in at least one given visual gaze direction, the visual correction being based on wearer data including the individual's prescription data.

[0009] The method includes the following steps:

[0010] - Determine the parameters related to the accommodative dynamics of the individual's eye.

[0011] - The ophthalmic lens is determined based on the wearer data and parameters related to the accommodative dynamics of the individual's eye.

[0012] Therefore, the method according to the invention allows for the personalization of ophthalmic lenses to meet individual needs by taking into account the individual's accommodative dynamics, thereby facilitating changes in optical power to focus on objects at different distances and improving the individual's comfort.

[0013] In an embodiment, when the parameters related to the individual's accommodative dynamics fall within a predetermined range, the at least one given visual gaze direction includes a first visual gaze direction corresponding to the dominant visual gaze direction. In this case, the step of determining the ophthalmic lens further includes defining the ophthalmic lens as having a complex surface having a substantially umbilical meridian and an average spherical gradient greater than or equal to 0.25 diopters and less than 2.0 diopters, and the value of the average spherical gradient is based on parameters related to the individual's eye's accommodative dynamics.

[0014] In one embodiment, the ophthalmic lens is a progressive lens, and the at least one given visual gaze direction further includes a second visual gaze direction different from the first visual gaze direction. In this case, the step of determining the progressive lens further includes defining a power variation curve from the far point to the near point based on parameters related to the accommodative dynamics of the individual's eye.

[0015] Parameters related to the accommodative dynamics of the individual's eye may include at least one of the following:

[0016] -The individual's rate of adjustment,

[0017] -The individual's non-regulated velocity,

[0018] -The individual's adjustment delay,

[0019] - This individual's non-regulatory delay.

[0020] Advantageously, the step of determining parameters related to the individual's regulatory dynamics is performed by means of measurements taken during a visual task performed by the individual.

[0021] In one embodiment, the step of determining the ophthalmic lens includes selecting an ophthalmic lens from a plurality of predetermined ophthalmic lenses based on parameters relating to the accommodative dynamics of the individual's eye.

[0022] Advantageously, the step of determining the ophthalmic lens is further based on the individual's age.

[0023] The method according to the invention may include a step of obtaining the individual's maximum accommodative amplitude before the step of determining the ophthalmic lens, and the step of determining the ophthalmic lens is based on the individual's maximum accommodative amplitude.

[0024] This allows for further personalization of the ophthalmic lens.

[0025] Advantageously, the step of determining the ophthalmic lens is further based on at least one of the following parameters: individual mobility curve, individual refractive error, and individual mobility device category.

[0026] Another object of the present invention relates to an optometric apparatus for determining said parameters related to the accommodative dynamics of an individual in a method according to the invention, wherein the optometric apparatus comprises:

[0027] - A light refraction unit configured to perform an objective measurement of the refractive characteristics of the individual's eye.

[0028] - A display system configured to alternately display a distant target to the individual at a first distance and a near target to the individual at a second distance during a visual task.

[0029] - A processing unit, which is connected to the light refraction unit and is configured to:

[0030] - During this visual task, multiple measurements are received sequentially from the light refraction unit over time, on a time-based basis.

[0031] - Based on these received measurements, parameters related to the accommodative dynamics of the individual's eye are determined.

[0032] Advantageously, the distant target is displayed to the individual on a first line of sight, and the near target is displayed to the individual on a second line of sight that is tilted downward relative to the first line of sight.

[0033] In one embodiment, the display system includes a near-viewing display and a far-viewing display, which are different from each other and are positioned at different optical distances from the individual's eyes.

[0034] For example, the near-viewing display and / or the far-viewing display is a smartphone or tablet screen.

[0035] Advantageously, the near-vision display is mechanically connected to the light refraction unit.

[0036] In this embodiment, the light refraction unit includes two different synchronization modules, which are positioned near the distant target and near the near target, respectively. Attached Figure Description

[0037] The following description, which is presented with reference to the accompanying drawings which are considered to be non-limiting examples, will help to understand the invention and how it is implemented.

[0038] On the attached diagram:

[0039] - Figure 1It is a diagram of the light pattern recorded by the light refraction unit;

[0040] - Figure 2a and Figure 2b The principles of two variations of a first example of a first embodiment of a method for determining ophthalmic lenses according to the present invention are shown.

[0041] - Figure 3 The standard graduated curve of a graduated multifocal lens is shown;

[0042] - Figure 4 This is an illustration of an example of a task involving switching between viewing distance and near distance;

[0043] - Figure 5a and Figure 5b These are the gradient curves of two ophthalmic lenses determined in the first example of the second embodiment of the method according to the present invention.

[0044] - Figure 6 The principle of a second example of a second embodiment of the method for determining ophthalmic lenses according to the present invention is shown;

[0045] - Figure 7 The principle of a third embodiment of the method for determining ophthalmic lenses according to the present invention is illustrated;

[0046] - Figure 8 The principle of a variation of the method for determining ophthalmic lenses according to the present invention is demonstrated. Detailed Implementation

[0047] This invention proposes to consider individual accommodative dynamics parameters when determining ophthalmic lenses in order to reduce accommodative effort when switching from distance vision to near vision (or vice versa) (e.g., when using electronic devices such as laptops, smartphones, or tablets).

[0048] Accommodation is the adjustment of the eye's optics so that an object is focused on the retina as the distance of the object from the eye changes. This is the process of adjusting the optical power of the eye's optics. More specifically, the term "accommodation" refers to the adjustment from a distant object to a near object, while the term "non-accommodation" refers to the relaxation of accommodation, i.e., the change in optical power from a near object to a distant object.

[0049] Accommodation kinetic parameters include parameters such as an individual's accommodative speed (e.g., assessed in diopters per second), individual's non-accommodative speed (e.g., assessed in diopters per second), individual's accommodative delay, and individual's non-accommodative delay. Accommodative delay is the duration between the onset of the accommodative stimulus and the moment when the individual begins the diopter change required to perform that accommodative action. Non-accommodative delay is the duration between the onset of the non-accommodative stimulus and the moment when the individual begins the diopter change required to perform that non-accommodative action. Another accommodative kinetic parameter is the maximum accommodative amplitude (e.g., assessed in diopters).

[0050] These adjustment kinetic parameters can be measured using the optometric apparatus according to the invention, which will be described below.

[0051] In one embodiment, the optometry device for determining parameters related to an individual's accommodative dynamics includes a light refraction unit, a display system, and a processing unit.

[0052] Optometry devices are designed for use while an individual is performing a visual task. Visual tasks involve either accommodation or non-accommodation.

[0053] The light refraction unit can be held in the hand of an individual and configured to perform an objective measurement of the refractive characteristics of the individual's eye in accordance with the principles described below.

[0054] Light is sent from a light source located in the light refraction unit to an individual's eye to illuminate the individual's pupil. The light then enters the individual's eye, is reflected by the retina, and then passes through the eye again to reach a camera located in the light refraction unit, the aperture of which is located in the same plane as the light source.

[0055] The camera records a light pattern LP, the shape, size, and orientation of which are at least related to the individual's eye refractive error. The light pattern LP may further be related to intrinsic parameters of the light refraction device, such as the position of the light source relative to the camera aperture, the size and shape of the camera aperture, the brightness of the light source, and the camera exposure parameters, as well as extrinsic parameters, such as the measurement distance and the center position of the individual's eye in the camera's field of view.

[0056] Figure 1 This is a schematic diagram of such a light pattern LP. In this simplified figure, the light pattern LP has the shape of a partial disk included in the pupil P and iris I of an individual's eye. The processing unit is configured to calculate the individual's eye refractive error based on the shape, size, and orientation of the light pattern recorded in real time. For example, the temporal evolution of an individual's eye refractive error during a visual task can be recorded by the light refraction unit. Therefore, accommodative characteristics can also be dynamically evaluated when an individual performs different tasks requiring accommodative variations.

[0057] The display system is used by individuals to perform visual tasks aimed at assessing their accommodation dynamics parameters. The system includes a distance display showing distant targets and a near display showing near targets. The distance display shows distant targets at a distance of approximately 5 to 6 meters from the individual. The near display shows near targets at a distance of approximately 30 to 40 centimeters from the individual. The display system is synchronized with a light refraction device to ensure good control over the measurements.

[0058] For example, the distance display can be a conventional visual acuity chart, and the distance target can be a given line on the conventional visual acuity chart. For example, the near display can be a microdisplay supplementing the light refraction unit. Alternatively, the near display can be a smartphone or tablet. Advantageously, the near display and the light refraction unit are mounted on the same system. Alternatively, the near display and the light refraction unit are mechanically linked.

[0059] Near targets can be composed of various letters, the size and contrast of which can be adjusted according to the difficulty of the accommodative response to be evaluated.

[0060] To simulate typical near vision and assess natural accommodative response dynamics, a distance target is displayed in front of the subject at eye level, while a near target is displayed approximately 30° below the principal angle of view. The principal angle of view clearly corresponds to the horizontal axis. This represents an advantage over existing optometric devices specifically designed to assess accommodative dynamics, as this positioning of the near target allows for measurements that more closely approximate natural posture or behavior, for example, when viewing a smartphone.

[0061] A method for measuring the accommodation dynamics parameters of an individual by means of an optometric apparatus according to the invention will now be described.

[0062] The principle is, for example, to observe in real time the light pattern recorded by the camera of the light refraction unit at a frequency of at least 25 Hz; and to monitor the temporal evolution of his or her eye's refractive error when an individual performs a visual task involving a modulating response.

[0063] Therefore, the display system is configured to alternately display a distant target to an individual at a first distance and a near target to the individual at a second distance during a visual task. The processing unit is connected to the light refraction unit and is configured to:

[0064] - During the vision task, multiple measurements are received sequentially from the light refraction unit over time, on a time-based basis.

[0065] - Based on these received measurements, parameters related to the accommodative dynamics of the individual's eye are determined.

[0066] Parameters related to the accommodative dynamics of an individual's eye can be calculated in real time based on the received measurements. In a variant, the measurements can be recorded in a dedicated memory.

[0067] In one embodiment, the method includes measuring an individual's accommodation dynamics parameters, such as his accommodation speed or his accommodation delay. The individual is instructed to gaze at a distant target, and once he or she detects a valid display of a near target (e.g., letters), he or she is instructed to gaze toward the near target. Alternatively, the individual is instructed to gaze toward the near target when the near display emits a specific light signal (e.g., light from an LED).

[0068] The moment when effective display of the near target occurs is used as the time baseline for evaluating the accommodation kinetic parameters. Measurements are taken using the light refraction unit and processed by the processing unit, starting from this time baseline, or preferably a few seconds (e.g., 0.5 seconds) before it. After completing this first task, the individual's gaze returns to the distant target. This task is repeated at least twice. Preferably, five trials are performed. The accommodation kinetic parameters are evaluated as the average of all results derived from measurements taken during different trials.

[0069] In another embodiment, the method includes evaluating both accommodative and non-accommodative dynamics, for example, an individual's non-accommodative speed or delay in addition to their accommodative speed or accommodative delay. To evaluate an individual's non-accommodative dynamics, the visual task includes instructing the individual to shift their gaze from a near target to a far target. More specifically, once, for example, a letter is displayed, the individual is instructed to maintain their gaze on the near target. Then, once the letter disappears, or at the onset of any other triggering signal, the individual must gaze back to the far target. Preferably, three to five far-to-near and near-to-far gaze transitions are performed to obtain the average of the accommodative and non-accommodative dynamic parameters.

[0070] In another embodiment, the light refraction unit includes two evaluation modules, one located in front of the individual to evaluate changes in distance vision, and the other located approximately 30° downwards and at a distance of 30 or 40 cm. Using two synchronized modules is meaningful for several reasons. For example, if positioned near a corresponding target (near or far), the corresponding module can capture images with the user's eyes facing the camera, providing a more easily interpretable light refraction acquisition. Similarly, using two different modules allows for optimization of the position of its light source and, more generally, optimization of its optomechanical properties relative to different measurement distances.

[0071] In the previously described embodiments, the modulated or non-modulated response is driven by a stimulus.

[0072] In another embodiment, the visual task includes voluntary gaze shifts, thereby causing voluntary or non-accommodative adjustments. An eye-tracking system is used to follow the individual's eye movements and thus determine when the individual shifts from viewing a distant target to viewing a near target and vice versa. The eye-tracking system is synchronized with the light refraction unit and the display system.

[0073] In all these embodiments, accommodative dynamics parameters can be evaluated based on the temporal evolution of an individual's ocular refractive error obtained from the processing unit. More precisely, mathematical models can be used to fit these temporal evolutions. An example of a mathematical model is the exponential model found in the following paper: "Amplitude-dependent accommodative dynamics in humans" by Kasthurirangan and Vilupuru.

[0074] y(t)=y0+a(1-e -t / τ )

[0075] Where y0 represents the individual's eye refractive error (in diopters) at the start of an accommodative or non-accommodative stimulus, y(t) represents the individual's eye refractive error over time during the accommodative or non-accommodative period of the visual task, and a and τ are constants.

[0076] By fitting this model to segments of measured temporal evolution of eye refractive errors corresponding to far-to-near or near-to-far transitions, parameters related to individual accommodative dynamics can be determined using measurements such as duration and slope.

[0077] It should be noted that different methods for determining an individual's accommodative dynamics parameters can be performed with the naked eye or, if the individual has refractive errors, with corrective lenses. The results will differ depending on whether or not a corrective lens is used if the individual has refractive errors. For example, if an individual has -1.00 diopters of myopia and is not wearing corrective lenses, his or her refractive error is -1.00 diopters. If an accommodative stimulus is provided at 40 cm, he or she will adjust by 1.5 diopters. However, if the same individual performs accommodation while wearing an ophthalmic corrector (i.e., a -1.00 diopters lens), he or she will adjust by 2.5 diopters, like an emmetropic person. Therefore, caution must be exercised when implementing different methods, regardless of whether the individual wears an ophthalmic corrective device.

[0078] Furthermore, it should be understood that the visual task is performed with both eyes open, but the parameters related to the accommodative dynamics of the eye are evaluated for at least one eye. The obtained values ​​can then be considered valid for both eyes.

[0079] The following describes a method according to the invention for determining an ophthalmic lens intended for individual wear to facilitate switching between distance and near vision. The ophthalmic lens will be determined to be suitable for providing visual correction to an individual in at least one given visual fixation direction, said visual correction being based on wearer data including individual prescription data. The prescription data includes the values ​​of optical power and astigmatism at the distance point of the ophthalmic lens as defined in ISO 13666:2012 §5.16, and the additional power (where appropriate).

[0080] The method includes the following steps:

[0081] - Determine the parameters related to the accommodative dynamics of an individual's eye.

[0082] - The ophthalmic lens is determined based on both wearer data and parameters related to the individual's accommodative dynamics.

[0083] The parameters related to the individual's regulatory dynamics can be one of the previously defined parameters.

[0084] For example, parameters related to an individual's accommodative dynamics can be determined by measuring parameters related to an individual's accommodative dynamics using an optometric apparatus according to the invention.

[0085] In the first embodiment, the parameter related to the accommodative dynamics of an individual's eye is the accommodative speed of the eye.

[0086] In this first example of the first embodiment, the ophthalmic lens is determined by custom-designing it based on the eye's accommodative speed. The custom-designed ophthalmic lens is designed with additional optical power at a given reference point in its lower half to facilitate near vision. The basic principle used in this first example is to correlate the amount of additional optical power enhancement (expressed in diopters) with the individual's accommodative speed. Preferably, the additional optical power enhancement decreases as the accommodative speed increases.

[0087] Here, an accommodation rate of 15 diopters per second is considered normal, or in other words, optimal. Therefore, zero additional optical power is associated with this accommodation rate value. Conversely, zero accommodation rate is associated with at least 1.1 diopters of additional optical power. In this first example, the affine function relating these two extreme points is used to assign additional optical power to a given accommodation rate value. Figure 2a This demonstrates the affine function.

[0088] In the variant, a psychometric function determined by psychometric measurements can be used to attribute additional optical power to a given accommodation rate. Figure 2b This demonstrates a psychometric function. This psychometric function can be a sigmoid function or an inverse logistic S-curve.

[0089] In the second example of this first embodiment, a given adjustment speed range corresponds to an ophthalmic lens Ld, which is designed to reduce user fatigue when performing near vision activities.

[0090] Ophthalmic lenses (Ld) of this design can have complex posterior surfaces, such as those described in U.S. Patent US7,540,610B2. These lenses have a substantially umbilicmeridian and a mean spherical gradient (referred to as enhancement) greater than or equal to 0.25 diopters and less than 1.10 diopters. The meridion of the complex surface is the line formed by the intersection of the wearer's average gaze direction as they transition from distance to near vision with the complex surface. This mean spherical gradient is defined as the difference between two reference points (the center point and a given reference point).

[0091] Based on this design, the following lenses can be considered:

[0092] - Lens 1: This lens provides an additional 1.1 diopter of optical power enhancement;

[0093] - Lens 2: This lens provides an additional 0.85 diopters of optical power enhancement;

[0094] - Lens 3: This lens provides an additional 0.60 diopter of optical power enhancement;

[0095] - Lens 4; This lens provides an additional 0.40 diopter of optical power enhancement.

[0096] Alternatively, the designed ophthalmic lens Ld can be of lens type 5 as described in European patent application EP 3547013 A1. More precisely, this type of ophthalmic lens is a single-vision ophthalmic lens having at least a prescription optical power, such that when fixated at a first distance, it provides the prescription optical power to the wearer under standard wearing conditions in at least a first gaze direction, and when fixated at a second distance, it provides the prescription optical power to the wearer under standard wearing conditions in at least a second gaze direction, the first distance and the second distance being different and the first gaze direction and the second gaze direction being different.

[0097] Lens 5 is a single-vision lens that has an optimized shape when viewed in the second viewing direction in order to introduce low optical aberrations.

[0098] The previously mentioned correspondence between the adjustment speed range and the lens d can be established as follows.

[0099] If an individual has an accommodative speed of 2.49 diopters per second or less, the enhancement value is determined to be 1.1 diopters. For example, lens 1 can be selected. If an individual has an accommodative speed between 2.50 and 4.99 diopters per second, the enhancement value is determined to be 0.85 diopters. For example, lens 2 can be selected. If an individual has an accommodative speed between 5.00 and 7.49 diopters per second, the enhancement value is determined to be 0.60 diopters. For example, lens 3 can be selected. If an individual has an accommodative speed between 7.50 and 9.99 diopters per second, the enhancement value is determined to be 0.40 diopters. For example, lens 4 can be selected. If an individual has an accommodative speed equal to or greater than 10 diopters per second, the ophthalmic lens can be determined to be a conventional single-vision lens (preferably an optimized single-vision lens) and can be selected as lens 5. The numerical values ​​of accommodative speeds defining the above different accommodative speed ranges are given as non-limiting examples, and other values ​​can be selected.

[0100] In the third example of the first embodiment, existing lenses can be selected to correspond to different adjustment speed ranges.

[0101] In the second embodiment, the parameter related to the accommodative dynamics of an individual's eye is the maximum accommodation of the eye.

[0102] In this first example of the second embodiment, the ophthalmic lens is determined by custom-designing it based on the eye's maximum accommodation. In this first example, the custom-designed ophthalmic lens is a progressive multifocal lens with a custom-designed gradient curve. The gradient curve of the progressive multifocal lens is a curve representing a gradual change in power along a lens meridian extending between the distance vision zone and the near vision zone (with an intermediate vision zone in between). This first example is suitable for older individuals who frequently switch between one lens region and another, such as between the distance vision zone and the intermediate vision zone, or, for example, between the intermediate vision zone and the near vision zone, or between the distance vision zone and the near vision zone.

[0103] Figure 3 The standard progressive curve of a progressive multifocal lens is shown for an elderly individual who requires 1.75 diopters of additional light for near activities. It is assumed that this individual has a maximum accommodation of 1.75 diopters.

[0104] like Figure 4 As shown, this individual frequently scans between his laptop screen, located approximately 80 cm away, and a board, located 5 m away. According to the gradient curve, this individual has only 0.25 diopters of accommodation remaining to switch from his laptop screen to the board and vice versa. Therefore, to perform this dual task of switching back and forth between the two viewpoints, an accommodative or non-accommodative response of 1 diopters is required, which is more than half of the individual's maximum accommodation.

[0105] Furthermore, if the individual exhibits a long adjustment delay, dual tasks will be very uncomfortable, resource-intensive, and require a significant amount of time for focused management.

[0106] Figure 5a This demonstrates the first custom gradient curve tailored to this individual. This first custom gradient curve presents a faster portion from the distant reference point VL to the central reference point VI, allowing for faster focus changes to perform transitions between the laptop screen and the tablet.

[0107] Figure 5b This displays the gradient curve for a second custom design tailored to this individual. This second custom gradient curve is... Figure 3 The gradient curve is shorter. This means that in this design, it is assumed that the near viewing distance is shorter than that of the near viewing distance. Figure 3 The gradient curve is further away. Therefore, the additional focus corresponding to the viewing distance of the laptop screen is stronger, and less adjustment or non-adjustment is needed to perform the focus change when switching between the laptop screen and the board.

[0108] In the second example of the second embodiment, such as Figure 6 As shown, the maximum adjustment range (assessed in diopters) is divided into three sub-ranges A, B, and C, corresponding to 0 to 3 diopters, 3 to 7 diopters, and 7 to 15 diopters, respectively.

[0109] For each of the subranges A, B, and C, the adjustment speed range is also divided into five subranges with a width of 2.5 diopters per second.

[0110] If an individual has the maximum accommodation included in subrange A, then ophthalmic lenses can be selected as lens 1, lens 2, lens 3, lens 4, and lens 5 respectively for the accommodation speed subranges included between 0 diopters per second and 2.49 diopters per second, between 2.50 diopters per second and 4.99 diopters per second, between 5.00 diopters per second and 7.49 diopters per second, between 7.50 diopters per second and 9.99 diopters per second, and between 10.00 diopters per second and 12.50 diopters per second.

[0111] If an individual has the maximum accommodation included in subrange B, then ophthalmic lenses can be selected as lens 1, lens 2, lens 3, lens 4, and lens 5 respectively for the accommodation speed subranges included between 2.5 diopters per second and 4.99 diopters per second, between 5.00 diopters per second and 7.49 diopters per second, between 7.50 diopters per second and 9.99 diopters per second, between 10.00 diopters per second and 12.49 diopters per second, and between 12.50 diopters per second and 15.00 diopters per second.

[0112] If an individual has the maximum accommodation included in subrange C, then ophthalmic lenses can be selected as lens 1, lens 2, lens 3, lens 4, and lens 5 respectively for the accommodation speed subranges included between 5 diopters per second and 7.49 diopters per second, between 7.50 diopters per second and 9.99 diopters per second, between 10.00 diopters per second and 12.49 diopters per second, between 12.50 diopters per second and 14.99 diopters per second, and between 15.00 diopters per second and 17.50 diopters per second.

[0113] This method of determining ophthalmic lenses utilizes the fact that individuals exhibiting low maximum accommodation and slow accommodative speed require more assistance in their accommodation (through power enhancement). In contrast, individuals exhibiting high maximum accommodation and fast accommodative speed will require less assistance in accommodation through power enhancement.

[0114] The adjustment speed and maximum adjustment values ​​for the corresponding sub-ranges are given as non-limiting examples, and other values ​​can be selected.

[0115] In the third embodiment, as Figure 7 As shown, the parameter related to the accommodative dynamics of an individual's eye is the individual's accommodative delay. The age range is divided into multiple age groups. The correspondence between the subranges of accommodative delay values, age groups, and ophthalmic lenses designed to reduce fatigue when an individual performs near vision activities can be established as follows.

[0116] If an individual is under 30 years old, and if the individual has an accommodation delay of longer than 0.60 seconds, between 0.40 seconds and 0.59 seconds, between 0.20 seconds and 0.39 seconds, and shorter than 0.19 seconds, the ophthalmic lens can be selected as lens 5, lens 4, lens 3, and lens 2, respectively.

[0117] If the individual is between 30 and 40 years old, and if the individual has an accommodation delay longer than 0.64 seconds, between 0.48 and 0.63 seconds, between 0.32 and 0.47 seconds, between 0.16 and 0.31 seconds, and less than 0.15 seconds, the selected ophthalmic lens can be selected as lens 5, lens 4, lens 3, lens 2, and lens 1, respectively.

[0118] If an individual is over 40 years old, and if the individual has an accommodation delay of longer than 0.60 seconds, between 0.40 seconds and 0.59 seconds, between 0.20 seconds and 0.39 seconds, and shorter than 0.19 seconds, the selected ophthalmic lens can be selected as lens 4, lens 3, lens 2, and lens 1, respectively.

[0119] It can be observed that high-intensity lenses are not considered for young individuals 1, while single-vision lenses are not considered for older individuals 5.

[0120] In fact, older individuals have more limited accommodative capacity, so proposing single-vision lenses without enhancement seems less meaningful. In contrast, younger individuals have less limited accommodative capacity, so proposing lenses with high enhancement seems less meaningful, and the optical aberrations resulting from such enhancement would cause a peripheral wimming effect and greater subjective discomfort than the potential benefits of accommodative changes.

[0121] Other variations of the previously described embodiments and examples are conceivable.

[0122] For example, ophthalmic lenses can be determined based on accommodation speed and an individual's age. The age range is divided into multiple age groups. The basic principle is that, for each age group, the enhancement value decreases as the accommodation speed increases. Figure 8 This demonstrates how the correspondence between age groups, accommodation speed subranges, and ophthalmic lenses designed to reduce fatigue when an individual performs near-vision activities can be made.

[0123] If an individual is under 30 years old, and if the individual has an accommodative speed of faster than 15 diopters per second, between 10 diopters per second and 14.99 diopters per second, between 5 diopters per second and 9.99 diopters per second, and slower than 4.99 diopters per second, then the ophthalmic lens can be selected as lens 5, lens 4, lens 3, and lens 2, respectively.

[0124] If an individual is between 30 and 40 years old, and if the individual has an accommodative speed of faster than 16 diopters per second, between 12 and 15.99 diopters per second, between 8 and 11.99 diopters per second, between 4 and 7.99 diopters per second, and slower than 3.99 diopters per second, then the selected ophthalmic lens can be selected as lens 5, lens 4, lens 3, lens 2, and lens 1, respectively.

[0125] If an individual is over 40 years old, and if the individual has an accommodative speed of faster than 15 diopters per second, between 10 diopters per second and 14.99 diopters per second, between 5 diopters per second and 9.99 diopters per second, and slower than 4.99 diopters per second, the selected ophthalmic lens can be selected as lens 4, lens 3, lens 2, and lens 1, respectively.

[0126] In this variant, it can be observed that high-intensity lenses 1 are not considered for younger individuals, while single-vision lenses 5 are not considered for older individuals.

[0127] In fact, older individuals have more limited accommodative capacity, so proposing single-vision lenses without enhancement seems less meaningful. In contrast, younger individuals have less limited accommodative capacity, so proposing lenses with high enhancement seems less meaningful, and the optical aberrations resulting from such enhancement would cause peripheral vertigo and greater subjective discomfort than the potential benefits of accommodative changes.

[0128] As in the previous examples, the values ​​for the adjustment speeds that define the above subranges are given as non-limiting examples, and other values ​​can be selected.

Claims

1. A method for determining an ophthalmic lens intended to be worn by an individual, the ophthalmic lens being adapted to provide a visual correction to the individual in at least one given visual gaze direction, the visual correction being based on wearer data comprising prescription data of the individual, wherein the method comprising the steps of: - determining a parameter related to the accommodation dynamics of the eye of the individual, - determining the ophthalmic lens based on the wearer data and the parameter related to the accommodation dynamics of the eye of the individual, wherein the parameter related to the accommodation dynamics of the eye of the individual is evaluated based on a temporal evolution of the refractive error of the eye of the individual, wherein the parameter related to the accommodation dynamics of the eye of the individual comprises at least one of the following parameters: - a non-accommodation speed of the individual, - an accommodation lag of the individual, - a non-accommodation lag of the individual.

2. The method according to claim 1, wherein: - when the parameter related to the accommodation dynamics of the individual belongs to a predetermined range, the at least one given visual gaze direction comprises a first visual gaze direction corresponding to a primary visual gaze direction, - the step of determining the ophthalmic lens further comprises defining the ophthalmic lens as having a complex surface having a substantially meridian equator and an average spherical power progression greater than or equal to 0.25 diopters and less than 1.10 diopters, - the value of the average spherical power progression is based on the parameter related to the accommodation dynamics of the eye of the individual.

3. The method of claim 1, wherein, the ophthalmic lens is a progressive lens, - when the parameter related to the accommodation dynamics of the individual belongs to a predetermined range, the at least one given visual gaze direction comprises a first visual gaze direction corresponding to a primary visual gaze direction, the at least one given visual gaze direction further comprises a second visual gaze direction different from the first visual gaze direction, the step of determining the ophthalmic lens further comprises defining a power variation curve from a distance vision point to a near vision point based on the parameter related to the accommodation dynamics of the eye of the individual.

4. The method of claim 1, wherein, the parameter related to the accommodation dynamics of the eye of the individual further comprises an accommodation speed of the individual.

5. The method of claim 1, wherein, the step of determining the parameter related to the accommodation dynamics of the eye of the individual is performed thanks to measurements during a visual task performed by the individual.

6. The method of claim 1, wherein, the step of determining the ophthalmic lens comprises selecting an ophthalmic lens among a plurality of predetermined ophthalmic lenses based on the parameter related to the accommodation dynamics of the eye of the individual.

7. The method of claim 1, wherein, the step of determining the ophthalmic lens is further based on the age of the individual.

8. The method according to claim 1, comprising, before the step of determining the ophthalmic lens, a step of obtaining a maximum amplitude of accommodation of the individual, wherein the step of determining the ophthalmic lens is based on the maximum amplitude of accommodation of the individual.

9. The method of claim 1, wherein, the step of determining the ophthalmic lens is further based on at least one of the following parameters: a mobility curve of the individual, a refractive error of the individual, a class of mobile device of the individual.

10. An optometric device for determining, in a method according to claim 5, the parameter related to the accommodation dynamics of the eye of an individual, the optometric device comprising: - an optical refraction unit configured to perform a measurement of the objective refraction characteristics of the eye of the individual, - a display system configured to display alternately to the individual, during a visual task, a distance-vision target at a first distance and a near-vision target at a second distance, - a processing unit connected to the optical refraction unit and configured to: - receive successively, as a function of time, a plurality of measurement values from the optical refraction unit, during the visual task, - determine, from these received measurement values, the parameter related to the accommodation dynamics of the eye of the individual, wherein the parameter related to the accommodation dynamics of the eye of the individual is evaluated on the basis of the temporal evolution of the refractive error of the eye of the individual, wherein the parameter related to the accommodation dynamics of the eye of the individual comprises at least one of the following parameters: - the non-accommodation speed of the individual, - the accommodation latency of the individual, - the non-accommodation latency of the individual.

11. The system of claim 10, wherein, the distance-vision target is displayed to the individual on a first line of sight and the near-vision target is displayed to the individual on a second line of sight tilted downward relative to the first line of sight.

12. The system of claim 10, wherein, the display system comprises a near-vision display and a distance-vision target display, the near-vision display and the distance-vision display being distinct and positioned at different optical distances from the eye of the individual.

13. The system of claim 12, wherein, the near-vision display and / or the distance-vision display is a smartphone or tablet screen.

14. The system of claim 12, wherein, the near-vision display is mechanically linked to the optical refraction unit.

15. The system of claim 10, wherein, the optical refraction unit comprises two synchronization modules, respectively positioned in the vicinity of the distance-vision target and in the vicinity of the near-vision target.

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