Method for determining an optical filter for a transparent support based on a determined personal photosensitivity

Abstract

The present invention provides a method for determining at least one filter for a transparent support, the method comprising the following steps: - determining a quantity representing a user's photosensitivity threshold; - determining, for each light environment in a group of light environments, an index representing a level of protection required by the user; - determining a score for each light environment in the group of light environments (40) and for each filter in a group of filters, the score representing the ability of the filter to achieve the level of protection required by the user; - determining at least one filter in the group of filters based on the scores of the at least one filter in multiple light environments (40) in the group of light environments.

Description

[0001] The present invention relates generally to the field of photosensitivity.

[0002] More specifically, the present invention relates to a method for determining at least one optical filter intended to be placed in front of the eyes of a user, said filter being able to improve or maintain the visual comfort and / or visual performance of said user.

[0003] The invention also relates to a computer system and a computer program product comprising code instructions for executing the method.

[0004] It has been observed that most people (close to 9 out of 10 people) experience light sensitivity. It can be a headache, pain, dizziness or a feeling of fatigue. It is a visual discomfort that can occur in many lighting conditions, especially lighting conditions that are specific to a given user.

[0005] Both users and eye care professionals (ECPs) are aware of the light sensitivity problem, but in most cases it is difficult to have a dialogue and find a solution to this specific problem. In fact, it seems that known methods are unable to satisfactorily determine a filter that is truly adapted to the user's personal light sensitivity.

[0006] These known methods for determining optical filters are generally based on the following process:

[0007] - is subjective, and therefore overly reliant on the user's judgement, or

[0008] - objective, but limited to measurements made on the user, whereas photosensitivity issues include a significant component perception based on user perception.

[0009] In both cases, neither the subjective nor the objective methods can determine all factors of the photosensitivity problem, making the determined filters not fully adapted to the individual needs of the user.

[0010] One problem that the present invention aims to solve is therefore to provide a method that allows determining a filter for a transparent support that better meets the level of protection required by the user, taking into account his perception of visual discomfort.

[0011] In order to solve this problem, the present invention provides a method for determining at least one filter for a transparent support, which filter is capable of improving or maintaining the visual comfort and / or visual performance of the user, the method comprising the following steps:

[0012] - determining a quantity representative of the user's photosensitivity threshold;

[0013] - determining, for each light environment in a set of light environments, an index representing the level of protection required by the user;

[0014] - determining a score for each light environment in the set of light environments and for each filter in the set of filters, said score representing the ability of the filter to achieve the level of protection required by the user;

[0015] - determining at least one filter in the set of filters based on a score of the at least one filter in a plurality of light environments in the set of light environments.

[0016] This method proposes to determine the filter by taking into account both the quantity representing the photosensitivity threshold (i.e., an objective parameter or a parameter obtained using a measurement / calculation process) and the level of protection required by the user himself (i.e., a subjective parameter). Thus, the filter is determined from a series of parameters that take into account both the user's physical response to light stimuli and the user's perception of a predetermined uncomfortable light environment to better determine the user's needs. Thus, a filter can be provided to the user that better meets the level of protection required for a given light environment and is specific to their personal needs.

[0017] According to an embodiment of the determination method, the set of light environments is selected in a set of environments; each environment in the set of environments is associated with a given light level.

[0018] According to an embodiment of the determination method, a plurality of environments of the set of environments are associated with mutually different light levels.

[0019] According to an embodiment of the determination method, the set of light environments is selected among the set of environments based on a questionnaire evaluating the reproducibility of each light environment of the user and / or the discomfort level of each light environment of the user.

[0020] According to an embodiment of the determination method, an index representing a level of protection required by a user in a given light environment of the set of light environments is calculated based on the light level associated with said light environment and the determined photosensitivity threshold.

[0021] According to an embodiment of the determination method, a score is calculated for a given filter and a given light environment based on an index representing the level of protection required by a user in said light environment and an index representing the protection provided by said filter.

[0022] According to an embodiment of the determination method, an index representative of the protection provided by a given optical filter is determined based on the light transmittance of the given optical filter.

[0023] According to an embodiment of the determination method, the photosensitivity threshold is determined using an apparatus configured to expose a user to increasing light levels and determine the photosensitivity threshold of the user based on user feedback representative of discomfort.

[0024] According to an embodiment of the determination method, the photosensitivity threshold is determined when the user is exposed to at least one light condition among warm light, cold light and flashing light.

[0025] According to an embodiment of the determination method, the step of determining at least one filter comprises the following steps:

[0026] - associate each score with a value representing the compliance of a given filter in a given light environment, given the level of protection required by the user;

[0027] - calculating, for a plurality of filters in the set of filters, a sum of values ​​of a plurality of light environments; and

[0028] - Rank multiple filters using the sum obtained in the previous step.

[0029] According to an embodiment of the determination method, the method further comprises at least one of the following steps:

[0030] - displaying the photosensitivity threshold on a display device using a predetermined scale based on a population baseline,

[0031] - displaying on the display device a discomfort level representative of the discomfort level declared by the user for each light environment of the set of light environments,

[0032] - displaying at least one filter determined in the set of filters on a display device.

[0033] According to an embodiment of the determination method, the method is a computer-implemented method.

[0034] The present invention also provides a computer system for determining at least one filter for a transparent support, the filter being capable of improving or maintaining the visual comfort and / or visual performance of a user, the system comprising:

[0035] - processor; and

[0036] a memory having computer code instructions stored thereon, the memory being operatively coupled to the processor, such that when executed by the processor, the computer code instructions cause the computer system to perform a method for determining at least one filter for a transparent support, the filter being capable of improving or maintaining visual comfort and / or visual performance of a user, the method comprising the steps of:

[0037] Determining a quantity representative of the user's photosensitivity threshold;

[0038] Determine, for each light environment in a set of light environments, an index representing the level of protection required by the user;

[0039] determining a score for each light environment in the set of light environments and for each filter in the set of filters, the score representing the ability of the filter to achieve the level of protection required by the user;

[0040] - Determining at least one filter in the set of filters based on a score of the at least one filter in a plurality of light environments in the set of light environments.

[0041] The present invention further provides a computer program product comprising code instructions for executing a method for determining at least one filter for a transparent support, the filter being capable of improving or maintaining the visual comfort and / or visual performance of a user, the method comprising the following steps:

[0042] Determining a quantity representative of the user's photosensitivity threshold;

[0043] Determine, for each light environment in a set of light environments, an index representing the level of protection required by the user;

[0044] determining a score for each light environment in the set of light environments and for each filter in the set of filters, the score representing the ability of the filter to achieve the level of protection required by the user;

[0045] - Determining at least one filter in the set of filters based on a score of the at least one filter in a plurality of light environments in the set of light environments.

[0046] The invention is described in more detail below by means of the drawings, which show only one preferred embodiment of the invention.

[0047] Figure 1 A flow chart of a filter determination method is schematically shown.

[0048] Figure 2 A photosensitivity test performed using a dedicated device is schematically shown.

[0049] Figure 3 Data recovery regarding photosensitivity test results displayed on a display device is schematically shown.

[0050] Figure 4 A table listing light environments that a user may encounter, with light components defined for each light environment, is schematically shown.

[0051] Figure 5 An image of a questionnaire displayed on a display device of a computer system is schematically shown, wherein a user is asked to assess the level of discomfort and reproducibility associated with a given light environment.

[0052] Figure 6The data restoration regarding the questionnaire results displayed on the display device is schematically shown.

[0053] Figure 7 A luminance scale is schematically shown, on which the luminance of the light environment and the photosensitivity threshold of the user are highlighted.

[0054] Figure 8 A flow chart showing the score determination steps.

[0055] Fig. 9 A table collecting reference filters and associated light transmittance and filter index is schematically shown.

[0056] Fig.10 A table collecting reference filters and associated scores for each selected light environment is schematically shown.

[0057] Fig.11 The data recovery of the filter determination step displayed on the display device is schematically shown.

[0058] The present invention provides a method for determining at least one filter for a transparent support. According to a preferred embodiment, the filter determination method is a computer-implemented method. The present invention further provides a computer system and a computer program product, the computer system and the computer program product comprising code instructions for executing the method.

[0059] The filter determination method allows determining at least one filter that meets the protection level required by the user based on an improved determination of the user's photosensitivity. Photosensitivity refers to any relatively strong and prolonged reaction or change in comfort or visual performance with respect to temporary or continuous light flux or stimulation.

[0060] A "transparent support" refers to any support through which light can pass and which can be provided with a filter to modulate the light transmission. The transparent support may be any support intended to be placed on or in front of the user's eyes. In addition, the transparent support may be an ophthalmic lens, a lighting device, an illuminated display, a windshield, a head-mounted display (referred to as "HMD"), glass, glass of a portable terminal, etc.

[0061] "Optical filter" refers to any means capable of modulating light, in particular at least one component of light (see "4D" below). An optical filter may be a filter coating or may be used to provide the filtering function of a filter coating. An optical filter may be in the form of a passive filter (uniform, with a gradient or with spatial variation) or an active filter as a photochromic or electrochromic filter.

[0062] It has been observed that the light environment cannot be accurately defined by considering only a single parameter as light intensity, but is dynamic and consists of multiple components that allow a better description of the light environment. Light can be defined as comprising four main components (called "4D"): an intensity component, a spatial component, a temporal component, and a spectral component.

[0063] The intensity component refers to the luminous flux emitted by the light source (in lumens). The intensity component causes an illuminance (in lux) at the wearer's location. The illuminance can be determined using a light sensor placed at the user's eye location that measures the illuminance (in lux) caused by the light source. Some factors that affect the illuminance are the energy intensity of the light source (the initial amount), the distance between the user and the light source (the amount at any point along the light path), and any changing elements in the light path (air, clouds, filters, reflectors, etc.). For example, the amount of outdoor light a person is exposed to can vary depending on geographic location, season, time of day, local weather, etc.

[0064] The spatial component is the relative position of the light source with respect to the user. This relative position depends on the angular distance between the user and the light source. The spatial component can be point-like or broad, and it can affect an individual's perception of light. Thus, for a given radiant flux, a point-like light source will have a higher brightness due to its smaller size. For example, a vehicle headlight with similar radiant flux will differ in brightness depending on its size and distance.

[0065] The temporal component defines the period of time during which the light source emits light. In practice, the light can be present for a short or long time, which can change the user's perception of the light. A given duration of exposure to light can be continuous or intermittent (the frequency can also vary). For example, a car headlight can contribute to the light environment for only a few seconds and move continuously across the field of view.

[0066] Spectral components refer to the spectrum of emitted light and its associated energy. This spectrum can be expressed using the wavelength of the light flux (in nanometers). As an example, the visible spectrum of light is contained between 380nm and 780nm. The light flux of white light can appear hotter or cooler depending on its spectrum.

[0067] The level of protection required by the user can be better defined when considering a determination method that takes into account all these light components to define the light environment. The contribution of this definition of light in the filter determination method will be explained in detail later in this description.

[0068] like Figure 1As shown, the filter determination method includes step 100 of determining a quantity representing a photosensitivity threshold of a user, step 200 of determining an index representing a level of protection required by the user for a specific light environment, step 300 of determining a score for each light environment and multiple filters, and step 400 of determining at least one filter based on the score determined in step 300.

[0069] The photosensitivity determination step 100 comprises determining a quantity representing the photosensitivity threshold of the user. This quantity is preferably illuminance expressed in lux.

[0070] The photosensitivity threshold may be determined based on measurements using a dedicated device. This dedicated device may be a device 10 configured to emit light toward one or both eyes of a user, such as Figure 1 As shown. The device 10 is configured to expose a user to increasing / decreasing light levels and determine the user's photosensitivity threshold based on user feedback representative of discomfort. The light intensity is increased or decreased to form a sequence of light changes. Preferably, this sequence includes increasing the light intensity to begin emitting light with an intensity that is comfortable for the user. The photosensitivity threshold is then determined depending on a response provided by the user. This response may be intentional, requiring the user to indicate when true disturbing discomfort occurs, or determined by an external device configured to detect the user's physical response to a given light flux. In both cases, the amount representing the user's photosensitivity threshold can be determined as the illuminance at which the user's response is detected.

[0071] Furthermore, photosensitivity thresholds can be determined for different colors of light to obtain thresholds reflecting cool white light or warm white light. Emitting light reflecting cool light or warm light, for example by emitting more blue light or more red light, allows simulating essentially artificial light or natural light or different light environments, respectively. Changing the color of the light emitted towards the user allows changing the spectrum. Thus, the photosensitivity of the user can be determined based on the change in the spectral components of the light.

[0072] This photosensitivity determination step 100 is performed, for example, as follows. The device 10 is placed in front of the user's eye and a light source emits a luminous flux towards the user's eye. A measurement sequence is performed, comprising three measurement steps. The first measurement step is a continuous light emission to cause the illuminance to increase in stages from a minimum to a maximum value, for example from 25 lux to 10211 lux. For example, the light emission may start with an illuminance of 25 lux, last for 5 seconds, in order to adapt the eye to the light conditions and cancel all previous exposures before the measurement, and then continue to increase the illuminance by 20% per second to the maximum illuminance. In a more general way, light may be emitted to cause an illuminance change from 25 lux to 15000 lux. This first measurement step is performed with warm light.

[0073] The second measurement step is the same as the first measurement step, but with cold light.

[0074] Then, the third measuring step is a flash emission to cause the illuminance to increase from a minimum value to a maximum value, increasing the illuminance in stages, for example from 25 lux to 8509 lux. The illuminance of the flash emission is preferably increased by at least 30%, preferably by 40%, most preferably by at least 44%. Before and between each flash emission, the user is exposed to a light emission below the minimum value of the illuminance of the flash emission (for example 10 lux). The duration of each flash emission is preferably 0.5 seconds, and the time between each flash emission is preferably 2 seconds.

[0075] According to a preferred embodiment, at least one of the first, second and third measurement steps is performed to determine the photosensitivity threshold of the user. Thus, a quantity representative of the photosensitivity threshold of the user is determined based on the results obtained with at least one of said first, second and third measurement steps. With regard to the above-mentioned definition of light, this photosensitivity determination step 100 allows determining a quantity representative of the photosensitivity threshold based on the variations of the intensity, spatial, temporal and spectral components of the light. A global interpretation of the photosensitivity profile of the user can be defined so that the user corresponds to a predetermined photosensitivity category, for example from much sensitive to none / slightly sensitive.

[0076] like Figure 3 As shown, the results obtained during the photosensitivity determination step 100 can be displayed on a display device such as a computer system screen. In particular, these results can include at least one photosensitivity threshold value determined in at least one of the first, second and third measurement steps. Preferably, each photosensitivity threshold value is shown as compared with a population baseline to allow the user to see their photosensitivity position based on photosensitivity baselines from a global population distribution. In addition, the previously determined photosensitivity category can also be displayed to inform the user of relevant issues and provide some suggestions.

[0077] According to an embodiment, the photosensitivity determination step 100 may include a simulation step before the first measurement step, wherein a continuous warm light is emitted towards the user. This simulation step allows the user to better understand how the device 10 works and to adapt the user's eyes to the light emission of the device 10.

[0078] The user index determination step 200 includes determining a user index representing a level of protection required by a user for each light environment in a set of light environments.

[0079] "User required protection level" refers to a protection level based on answers or inputs from the user himself via a questionnaire. Thus, the purpose of this user index determination step 200 is to determine the user's required protection (pre-existing conditions), which light conditions the user faces and from which he needs protection. Thus, this index determination step 200 allows determining and potentially selecting light conditions from which the best filter can be selected.

[0080] Light environments are common everyday situations that may be sources of light that are uncomfortable for the user. A set of light environments is selected in a set of environments, wherein each environment in the set of environments is associated with a given light level having a different light component or characteristic (e.g., intensity, spectrum, time and space components). In particular, the set of environments is preferably associated with mutually different combinations of light components or characteristics.

[0081] According to a preferred embodiment, each light environment is selected to depict a specific combination of 4D light components (intensity component, spatial component, spectral component and time component). Therefore, it is determined that the group as a whole has the most representative components of the 4D light components collected in different light environments. "Light environment" refers to a situation that symbolizes a specific light configuration through pictures and / or text. For example, a night situation can refer to a medium to high light intensity (intensity component) with a movable light source (spatial component), which can be emitted towards the user for only a few seconds (time component). The group of light environments preferably includes at least one outdoor situation, at least one indoor situation and at least one night situation. Each light environment can be symbolized by an image or a description representing the situation.

[0082] According to a preferred embodiment, the set of light environments includes: Figure 4 4D light environment 40. Each light environment 40 is defined by the level in each 4D light component 42 from the first level (one star) to the third level (three stars). The higher the level, the more important the component. When the component is not evaluated (no star) in the components, this component has no meaning in the light environment. For example, the light environment 40 corresponding to "night situation with digital devices" implies a medium level of light intensity, a medium level of spatial components due to the nature of the light source (such as a smartphone), a low level of spectral components, and the time component is not significant here because the light source is permanent or does not change over time.

[0083] The user is provided with an image or a description representing each light environment 40 in the set of environments. In both cases, the image and the description are configured to enable the user to understand or imagine the light conditions caused by the described light environment 40. The description can be provided to the user by displaying text on a display device and / or via an audio channel. For each light environment 40, the user is asked to evaluate the level of discomfort associated with the light environment 40 and / or the reproducibility of this light environment 40. "Reproducibility" refers to the frequency 40 with which the user is expected to be faced with this light environment.

[0084] According to a preferred embodiment, the light environment 40 is shown as representing Figure 5The image of this light environment 40 is shown. The user is asked to rate the level and frequency of discomfort associated with each light environment 40, for example on a scale of 0 to 4. Preferably, the user interacts with the computer system to provide his answer. The user's answer is preferably recorded on the memory of the computer system. The image of the light environment 40 is preferably displayed on the display device of the computer system.

[0085] The discomfort level of each light environment 40 in the group is then determined depending on the user's answers.

[0086] like Figure 6 As shown, the discomfort level obtained for each light environment 40 can be displayed on the display device of the computer system. In particular, these results can be arranged on a first graph 20 to allow the user to have a global view of their photosensitivity curve with respect to the light environment 40. In addition, a second graph 22 can be displayed showing the photosensitivity of the user compared to a population baseline to allow the user to see their photosensitivity position based on a photosensitivity baseline from a global population distribution.

[0087] According to a preferred embodiment, light environments 40 with higher discomfort levels are selected to determine an index representing the user protection level, called a user index. For example, if the scale is set to 0 to 4, only light environments 40 with discomfort levels higher than 2,5 can be selected to determine the user index. Therefore, a user index is determined for each light environment 40 that has been selected.

[0088] For a given light environment 40 in the set of light environments 40, a user index is determined by calculation based on the light level associated with the light environment 40 (intensity component) and the determined photosensitivity threshold determined in the photosensitivity determination step 100. In particular, the user index is preferably calculated as a ratio between the light level associated with the light environment 40 and the photosensitivity threshold. For example, when a photosensitivity threshold of 600 lux is determined in the photosensitivity determination step 100, the user index is equal to 10 for a light environment 40 having a light level of 6000 lux. This means that the light environment 40 is 10 times more intense than what a consumer can tolerate. Figure 7 As shown, the user index corresponds to the difference between the light level in a given environment ("target light condition") and the photosensitivity threshold of the user. The user index is then determined for each light environment 40, preferably for each selected light environment 40.

[0089] Then, a score is determined for each light environment 40 and the plurality of filters in a score determination step 300. Figure 8As shown, the score determination step 300 includes a step 310 for determining an index (referred to as a filter index) representing the protection provided by a given filter. Each filter of the plurality of filters is defined by at least a filtering capability. According to a preferred embodiment, the filtering capability comprises a light transmittance value (Tv) of the given filter. Light transmittance (Tv) is the ratio of the luminous flux transmitted by a lens or filter to the incident luminous flux. Light transmittance defines the percentage of light from the luminous flux transmitted through the filter. Thus, a surface with a light transmittance of 0% may prevent the entire luminous flux from passing through the surface, while a surface with a light transmittance of 100% may allow the entire luminous flux to pass through the surface without absorbing the luminous flux.

[0090] The light transmittance in the visible spectrum can be determined using the following equation:

[0091]

[0092] in

[0093] T(λ) is the spectral transmittance of the tinted eyeglass lens;

[0094] V(λ) is the spectral luminous efficiency function of daylight (see ISO / CIE 10527);

[0095] S D65λ (λ) is the spectral distribution of the radiation of illuminant D 65 according to the International Commission on Illumination standard (see ISO / CIE 10526).

[0096] The filter index determination step 310 first includes the step of determining the filtering capability of each filter in the plurality of filters. Then, the filter index of each filter is determined using the following equation:

[0097]

[0098] Thus, the filter index defines the amount of light that the filter cuts off. The filter may have a single light transmittance value (i.e. a fixed value) or multiple light transmittance values ​​as a photochromic or electrochromic lens. In the case where the filter is a variable filter, preferably lower and upper light transmittance values ​​are calculated to determine the suitability of the filter for the user for each lower and upper light transmittance value.

[0099] Fig. 9 An example of a table is shown which collects a plurality of reference filters 30, each having one or more light transmittance values ​​70, and using the above equations to determine the filter index 80. The filters shown in the table have light transmittances ranging from 5% to 100%.

[0100] The score determination step 300 further includes a score calculation step 320 for determining the score of each light environment 40 in the set of light environments 40 and each filter in a set of filters. The score represents the effectiveness of the filter in a given situation, i.e., the ability of a given filter to achieve the level of protection required by the user. Based on the user index in the given light environment 40 and the filter index of the given filter, the score of the given filter and the given light environment 40 is calculated. In particular, the score is calculated as the ratio between the user index and the filter for the given filter and the given light environment 40. For example, for a filter index of 6.67 and a user index of 6.67, the score is equal to 1. A score of 1 means that the filter covers 100% of the user protection requirements for the light environment 40. If the filter index is higher than 1, it means that the filter fully protects the user, so that light comfort is optimal, but there is a risk of vision loss.

[0101] Thus, the score is a score that represents the suitability of a given filter for a user in a given light environment 40. Providing a score for selected light environments 40 that have been identified by the user as having a high level of discomfort and / or reproducibility allows for assistance in determining the best protection for the user.

[0102] Fig.10 An example of a table is shown which collects a plurality of scores 50 determined based on a plurality of reference filters 30 for which the filter index has been determined in the filter index determination step 310 and a plurality of selected light environments 40 for which the user index 60 has been determined in the user index determination step 200. For example, it can be seen that for a user index of 20, for a filter index of 1, the score is equal to 5% (or 0.05). As another example, it can be seen that for a user index of 1.6, for a filter index of 1.54, the score is equal to 96% (or 0.96).

[0103] Then, a filter determination step 400 comprises determining at least one filter based on the score 50 determined at the score determination step 300. This filter determination step 400 aims to rank the filters based on the score 50 of the light environment 40 of the filters 30. Preferably, the filters 30 are ranked only with respect to the light environment selected by the user.

[0104] Each score 50 is associated with a value representing the compliance of a given filter 30 in a given light environment 40, given the level of protection required by the user. A global value can then be determined based on all the values ​​determined for the same filter. All the values ​​of the same filter for each light environment 40 or each selected light environment 40 can be added to obtain this global value. Multiple filters 30 are then ranked based on the global value.

[0105] According to a preferred embodiment, one or more filters are determined for at least two transparent supports having different purposes. For example, when the transparent support is an ophthalmic lens, one or more filters are determined for at least two glasses having different uses. One pair of glasses can be used as sunglasses, while another pair of glasses can be used as everyday glasses. The ranking of the filters is performed with respect to a specific light environment associated with the use of the transparent support.

[0106] According to a preferred embodiment, the closer the score is to 100%, the higher the value. In particular, scores from a low compliance threshold to a high compliance threshold can be associated with positive values, while scores beyond this compliance range can be associated with negative values. In doing so, the global value of each filter is weighted based on a predetermined degree of compliance with user needs. For example, the compliance range can be set to 86% to 200%. In addition, a score of 50 (e.g., a score below 50% and above 300%) that is considered to be significantly inconsistent with user needs can be associated with a low value. For example, a score between 86% and 200% is associated with a value of 2, a score below 50% or above 300% is associated with a value of -2, and a score of 51% to 85% or 201% to 299% is associated with a value of -0,5. Therefore, if filters with scores equal to 42, 104, 174, 123, and 185 are considered, the corresponding associated values ​​will be -2, 2, 2, 2, and 2. The global value, i.e., the sum of multiple values, is 6. The score that is summed is at least the score selected in the index determination step 200 .

[0107] One or more filters may then be determined to have the best compliance to the protection needs of the user. Preferably, at least two filters from different categories of filters are determined in order to provide the user or ECP with a wider list of compliant filters. Preferably, these different filter categories correspond to different purposes or different pairs of glasses. The different categories of filters may be filters intended to be placed on sunglasses and filters intended to be placed on everyday glasses.

[0108] like Fig.11As shown, one or more filters determined to best meet the user's protection requirements can be displayed on a display device of the computer system. In particular, information representing the compliance of each filter with respect to each light environment 40 or a selected light environment 40 can be displayed. The resolution percentage 90 of each filter can also be determined and optionally displayed based on the median of the efficiency percentages for all selected light environments 40 to give an overall performance of each filter.

[0109] As described above, the filter determination method may be a computer-implemented method that can be performed using code instructions from a computer program product or a computer system. The computer system includes a processor; and a memory having computer code instructions stored thereon. The memory is operably coupled to the processor so that when executed by the processor, the computer code instructions cause the computer system to perform the filter determination method.

Claims

1. A method for determining at least one filter for a transparent support, the filter being capable of improving or maintaining the visual comfort and / or visual performance of a user, the method comprising the following steps: - determining (100) a quantity representing the photosensitivity threshold of said user; - determining (200) for each light environment (40) of a set of light environments (40), an index (60) representing the level of protection required by the user, wherein the set of light environments (40) is selected from a set of environments; each environment of the set of environments is associated with a given light level, the set of light environments (40) being selected from the set of environments based on a questionnaire assessing the reproducibility of each light environment of the user and / or the level of discomfort of each light environment of the user; - determining (300) a score (50) for each light environment in the set of light environments (40) and for each filter in a set of filters, the score representing the ability of the filter to achieve the level of protection required by the user; - determining (400) at least one filter of the set of filters based on a score (50) of the at least one filter in a plurality of light environments (40) of the set of light environments.

2. The method according to claim 1, wherein: A plurality of environments in the set of environments are associated with light levels that differ from one another.

3. The method according to claim 1 or 2, wherein: An index (60) representing a level of protection required by the user in a given light environment (40) in the set of light environments is calculated based on the light level associated with the light environment and the determined photosensitivity threshold.

4. The method according to any one of claims 1 to 3, wherein: A score is calculated for a given filter and a given light environment (40) based on an index (60) representing the level of protection required by the user in the light environment and an index representing the protection provided by the filter.

5. The method according to claim 4, wherein: An index representing the protection provided by a given filter is determined based on the light transmittance (Tv) of said given filter.

6. The method according to any one of claims 1 to 5, wherein: The photosensitivity threshold is determined using an apparatus (10) configured to expose the user to increasing light levels and determine the user's photosensitivity threshold based on user feedback representative of discomfort.

7. The method according to claim 6, wherein: The photosensitivity threshold is determined when the user is exposed to at least one light condition of warm light, cool light, and flashing light.

8. The method according to any one of claims 1 to 7, wherein: The step of determining at least one filter comprises the following steps: - associating each score (50) with a value representing the compliance of a given filter in a given light environment (40) in view of the level of protection required by said user; - calculating, for a plurality of filters in the set of filters, a sum of the values ​​of the plurality of light environments (40); and - Ranking the plurality of filters using the sum obtained in the previous step.

9. The method according to any one of the preceding claims, further comprising at least one of the following steps: - displaying said photosensitivity threshold on a display device using a predetermined scale based on a population baseline, - displaying on the display device a discomfort level representative of the discomfort level declared by the user for each light environment of the set of light environments, - displaying on said display device at least one filter determined in said set of filters.

10. A method according to any one of the preceding claims, wherein: The method is a computer-implemented method.

11. A computer system for determining at least one filter for a transparent support, the filter being capable of improving or maintaining visual comfort and / or visual performance of a user, the system comprising: -processor; as well as - a memory having computer code instructions stored thereon, said memory being operatively coupled to said processor, such that when executed by said processor, said computer code instructions cause said computer system to perform a method for determining at least one filter for a transparent support, said filter being capable of improving or maintaining visual comfort and / or visual performance of a user, said method comprising the steps of: ● determining (100) a quantity representing the photosensitivity threshold of the user; for each light environment (40) in a set of light environments (40), determining (200) an index (60) representing the level of protection required by the user, wherein the set of light environments (40) is selected from a set of environments; each environment in the set of environments is associated with a given light level, the set of light environments (40) being selected from the set of environments based on a questionnaire assessing the reproducibility of each light environment of the user and / or the level of discomfort of each light environment of the user; Determining (300) a score (50) for each light environment in the set of light environments (40) and for each filter in a set of filters, the score representing the ability of the filter to achieve the level of protection required by the user; - Determining (400) at least one filter in the set of filters based on a score (50) of the at least one filter in a plurality of light environments (40) in the set of light environments.

12. A computer program product comprising code instructions for executing a method for determining at least one filter for a transparent support, the filter being capable of improving or maintaining visual comfort and / or visual performance of a user, the method comprising the steps of: ● determining (100) a quantity representing the photosensitivity threshold of the user; for each light environment (40) in a set of light environments (40), determining (200) an index (60) representing the level of protection required by the user, wherein the set of light environments (40) is selected from a set of environments; each environment in the set of environments is associated with a given light level, the set of light environments (40) being selected from the set of environments based on a questionnaire assessing the reproducibility of each light environment of the user and / or the level of discomfort of each light environment of the user; Determining (300) a score (50) for each light environment in the set of light environments (40) and for each filter in a set of filters, the score representing the ability of the filter to achieve the level of protection required by the user; - Determining (400) at least one filter in the set of filters based on a score (50) of the at least one filter in a plurality of light environments (40) in the set of light environments.

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