Patent Description:
Recent improvements in the field of ophthalmic lenses, have allowed providing customized optical lenses, such customization going beyond the wearer's prescription. Further parameters than the wearer's prescription may be considered when designing an ophthalmic lens, leading to an increase of the number of lens designs.

One of the parameters whose importance is more and more considered while determining the optical design of lenses to be provided to a wearer is the comfort of said wearer while using the optical lenses. Different known parameters significantly impact the wearer's perceived wearing quality or comfort of the optical lenses or the wearer's appreciation of the lens design. One of these parameters is the sensitivity to optical aberrations. Indeed, it is known that the wearer's comfort is highly influenced by the wearer's sensitivity to the perceived optical aberrations and errors associated with the lens design.

Moreover, the eye-head behavior or activity of the wearer may impacts the perception of such optical aberrations. Yet the head-eye coefficient which qualifies the individual wearer's propensity to rather move the head or rather move the eyes is not related to an intrinsic sensitivity of the wearer to optical aberrations. Indeed, two wearers with the same eye-head coefficient (COT1 = COT2) may have different sensitivities to optical aberrations and thus a different appreciation of the same lens design.

Therefore, the intrinsic sensitivity of the wearer to the different optical aberrations associated with optical lenses plays an important role in the wearer's appreciation of the lens design.

Usually the intrinsic sensitivity of the wearer to optical aberrations is determined by an ophthalmologist or optometrist in specific conditions that might influence the wearer. Indeed, the current methods implies a choice from the person that may disturb the result of the test and induce large change and variation depending on the context and situation. Thus current methods are not well adapted to evaluate subjective perception of optical aberrations.

Therefore there is a need for a method adapted to determine the subjective intrinsic sensitivity of a user to optical aberrations, and thus to evaluate the wearer's appreciation of a lens design that would give relevant and not fluctuating results in a fast and easy way.

One object of the present invention is to provide a method for easily evaluating the wearer's appreciation of a lens design corresponding to the level of acceptance of a user of a lens design.

Document <CIT> discloses a prior art method for determining a lens design of an optical lens adapted to a wearer.

To this end, the invention proposes a method according to claim <NUM>.

According to a further aspect, the invention further relates to a most appropriate lens design for a wearer determining device according to claim <NUM>.

The processes and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the desired method. The desired structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the inventions as described herein.

The invention is based on a method for determining the level of acceptance of a user of a lens design.

<FIG> illustrates the method for determining the level of acceptance of a user of a lens design. The method comprises at least:.

Every user reacts differently to each lens design and expresses preferences for certain types of lens design. Such preference can be evaluated by the level of acceptance of a user for a lens design, the level of acceptance of a user of a lens design representing its perceived quality or comfort while looking through the lens design.

In the sense of the invention the term "lens design" is a generic term which designates the set of parameters allowing defining a dioptric function of an ophthalmic lens. Furthermore, the lens design comprises different types of lens design such as monofocal lens designs, bifocal lens designs, and progressive addition lens designs among others.

Sensitivity of the user to optical aberrations can be determined objectively, for example thanks to a perception test, or subjectively by means of an image quality gradation test. This sensitivity to optical aberration can be manifested among others as discomfort (pitch) and/or a change of the perception of visual index (for example: curvatures), and/or motor skills (for example: modification of eye-head coordination, postural oscillation) and/or sensorimotor loops (for example: change in response times). The subjectively evaluated profile of the user's sensitivity to optical aberrations obtained by means of a gradation test forms the notation table.

As represented on <FIG>, the method for determining the level of acceptance of a user comprise a notation table receiving step S6 during which a notation table of the user is received. The notation table of a user corresponds to a table associating the user's subjective gradations of presented pictures with different levels of optical aberrations to said levels of optical aberrations.

Preferably, the method further comprises a notation table determining step S4, during which the user subjectively grades the quality of presented simulated images representing real optical errors or aberrations.

The gradation test consists in presenting to the user a first perfect image with no optical aberration. Simulated images corresponding to different level of degradation of the first perfect image and representing different levels of optical aberration are then successively and randomly presented to the user. The user associates to the presented image a subjective grade representing its perceived quality of the presented image. The user grades each image multiple times, the perfect image and simulated images being presented in random order.

With reference to <FIG>, the subjective perceived quality of the presented image can be quantified using a gradation scale. The different presented images with associated different optical aberrations are graded by the user by using a gradation scale.

As represented on <FIG>, the notation table of a user obtained by the gradation test can be expressed as a graphic representing the user's perceived quality of the presented image as a function of the different levels of optical aberrations.

Simulated images with induced optical aberration are obtained using a numerical simulation consisting in a convolution of a sharp image and a point-spread function including the spherical defocus, the astigmatism, other higher order geometrical aberrations, the chromatic aberration, pupil diameter, diffraction and diffusion. Moreover, the numerical simulation take into account the viewing distance and the size of the display.

Moreover, the numerical simulation of images takes into account the viewing distance at the time of the gradation test. The images can be simulated to correspond to images seen at a specific targeted distance. For example the images are simulated as if they were seen a near vision distance, intermediate vision distance or at far vision distance.

Additionally, the type of presented simulated images can be adapted to the targeted viewing distance at the time of the gradation test. For example, the presented simulated images can represent words or letters for near vision distance or a natural scene for far vision distance.

Furthermore, the presented simulated images can also be adapted to represent different viewing conditions such as standard vision, low light vision and/or night vision.

The presented simulated images may be graded using a <NUM>-items gradation scale, for example from <NUM> to <NUM> with steps of <NUM>. For example, the <NUM> items correspond respectively to excellent, good, fair, poor and bad image quality.

According to an embodiment of the invention, the presented simulated images the user have to grade are seen through real optics.

Preferably, the presented images are seen through a sphero-cylindrical correction giving at least a <NUM>/<NUM> high contrast visual acuity.

Preferably, the presented images are seen by the user through a <NUM> pupil. Advantageously, the use of a <NUM> pupil worn in front of the eye of the user allows limiting the impact of the user's own optical aberrations.

The gradation step is normally done in binocular condition with the two eyes open and used but can also be performed in monocular conditions.

As represented on <FIG>, the method for determining the level of acceptance of a user of a lens design may comprise prior to the notation determining step S4 a best eye determining step S2, during which the best eye of the user is determined and wherein the notation table determining step S4 is performed while using only the best eye.

The "best eye" is a generic term used to designate the eye with the best acuity, the eye with the lowest aberration level or the dominant eye.

Performing the notation determining step S4 in monocular conditions allows obtaining a more accurate evaluation of the perceived quality of the presented images.

As represented on <FIG>, lens designs can be represented by their variation of optical aberrations as a function of the angular view point in the horizontal field of view at a specific height, for example at the near vision height.

During the notation table associating step S10, the notation table of the user is associated to a lens design based on the set of optical aberrations. The association of a notation table representing the user's perceived quality of pictures as a function of the level of optical aberrations and a lens design representing variations of levels of optical aberrations as a function of the angular view point in the horizontal field of view at a specific height permits obtaining the user's perceived quality of pictures as a function of the angular view point in the horizontal field of view at a specific height.

As represented on <FIG>, the level of acceptance of a user of a lens design can be expressed as a function representing the user's perceived quality of pictures represented times the angular view point in the horizontal field of view at a specific height.

During the level of acceptance determining step S12, the level of acceptance of a user of a lens design is determined based on the association of the notation table of the user and on the lens design.

The level of acceptance of a user of a lens design represents a relevant and not fluctuating evaluation of the perceived quality and comfort of a user of a lens design.

The method for determining the level of acceptance of a user of a lens design may further comprises a displaying step S14 during which the design map of the user is displayed.

As represented on <FIG> the level of acceptance of a lens of a user is represented according to the invention as a design map. The design map which corresponds to the association of the notation table of a user and a lens design corresponds to another way to represent the level of acceptance of a user of a lens design.

The level of acceptance of a user of a lens design and the corresponding design map of a user of a lens design represent an evaluation of the visual performance of a user when using the lens design.

As represented on <FIG>, the method according to the claimed invention further comprises prior to the notation table associating step S10, a zone defining step S8 during which zones are defined on a lens design map. For example zones may be defined around the optical center of the lens, around the near vision zone and/or around the far vision zone.

For each defined zone of the lens design map, the notation table associating step S10 and the level of acceptance determining step S12 are carried out in order to determine a level of acceptance for each of the defined zones.

<FIG> illustrates the method of the claimed invention for determining the most appropriate lens design for a wearer.

During the notation table receiving step S20, the notation table of the user representing the user's sensitivity to optical aberrations is received.

Multiple different lens designs are further selected and the level of acceptance of a user for each selected lens design is determined during the level of acceptance determining step S22. The level of acceptance of the user of each lens design is determined based on the association of the notation table of the user and a lens design according to the above described method.

During the comparison step S26, the levels of acceptance of the multiple lens designs are compared together in order to determine the most appropriate lens design for the wearer.

The most appropriate lens design is determined during the lens design determining step S28. In an example not covered by the claimed invention, the most appropriate lens design for a wearer may correspond to the lens design with which the level of acceptance of the user is the higher.

The method for determining the most appropriate lens design for a wearer according to the invention further comprises prior to the comparison step S26 a zone defining step S23.

During the zone defining step S23, zones corresponding to each level of acceptance are defined on each designs maps. For examples zones of the design map with a level of acceptance comprises between <NUM> and <NUM> excluded correspond to the "very bad zone", between <NUM> and <NUM> excluded to the "bad zone", between <NUM> and <NUM> excluded to the "fair zone", between <NUM> and <NUM> excluded to the "good zone", and between <NUM> and <NUM> to the "very good zone".

The method for determining the most appropriate lens design for a wearer according to the claimed invention further comprises prior to the comparison step S26 a level of satisfaction determining step S24.

During the level of satisfaction determining step, a level of satisfaction is determined. The level of satisfaction designates the minimal acceptable level of acceptance of a lens design value.

The design maps of the multiple lens designs are compared during the comparison step S26 to determine the most appropriate lens for a wearer.

The most appropriate lens design for a wearer may correspond to the lens design with the smallest zone representing a level of acceptance lower than the level of acceptance.

Additionally the most appropriate lens design for a wearer may correspond to the lens design with the biggest zone representing a level of acceptance higher than the level of satisfaction.

<FIG> illustrates a method not covered by the claimed invention for determining at least an appropriate lens design for a wearer.

A first lens design is selected during the lens design selecting step S30.

During the level of acceptance determining step, the level of acceptance of a user for the selected lens design is determined according to the method based on the notation table and the lens design.

During the level of satisfaction determining step S34, a level of satisfaction corresponding the minimal acceptable level of acceptance of a user of a lens design is determined.

The level of acceptance of the user of the selected lens design is then compared to the level of satisfaction during the comparing step S38. If the level of acceptance is higher or equal to the level of satisfaction, the lens design is considered to be appropriated for the user.

Otherwise, if the level of acceptance of the user of the selected lens design is smaller than the level of satisfaction, the lens design is considered to be not appropriated for the wearer and steps S30 to S38 are repeated with a different lens design until at least one appropriate design is determined.

Additionally, the method for determining at least an appropriate lens design for a wearer may comprise prior to the comparing step S38 a weighted level of acceptance determining step S36 during which the level of acceptance of a user of a lens design is weighted by the percentage of use repartition.

The percentage of use repartition corresponds to the probability of use of the lens design at each point by the user.

The weighted level of acceptance of a user of the lens design is further compared to the level of satisfaction during the comparing step S38.

According to another aspect, the invention further relates to a computer product adapted to implement a method of the invention for determining the most appropriate lens design for a wearer.

A further example not covered by the claimed invention relates to a level of acceptance of a user of a lens design determining device configured for determining the level of acceptance of a user of a lens design.

The level of acceptance of a user of a lens design determining device comprises a communication unit configured to receive notation table data relating to a notation table of a user.

The notation table of a user corresponds to a set of subjective values representing the sensitivity of the user to a set of optical aberrations.

Furthermore, the level of acceptance of a user of a lens design determining device comprises a memory storing computer executable instructions and configured to store the received notation table data.

Moreover, the level of acceptance of a user of a lens design determining device comprises a processor for executing the computer executable instructions.

The computer executable instructions comprise instructions for determining the level of acceptance of a user of a lens design based on the notation table data.

According to another aspect, the invention further relates to a most appropriate lens design for a wearer determining device configured for determining the most appropriate lens design for a wearer.

The most appropriate lens design for a wearer determining device comprises a communication unit configured to receive levels of acceptance data.

The levels of acceptance date relates to the levels of acceptance of the user of multiple lens designs.

Furthermore, the most appropriate lens design for a wearer determining device comprises a memory storing computer executable instructions and configured to store the levels of acceptance data.

Moreover, the most appropriate lens design for a wearer determining device comprises a processor for executing the computer executable instructions.

The computer executable instructions comprise instructions for determining the most appropriate lens design for a wearer based on the levels of acceptance data and according to the method of the invention.

A further example not covered by the claimed invention relates to an appropriate lens design for a wearer determining device configured for determining an appropriate lens design for a wearer.

The appropriate lens design for a wearer determining device comprises a communication unit configured to receive levels of acceptance data.

Furthermore, the appropriate lens design for a wearer determining device comprises a memory storing computer executable instructions and configured to store the levels of acceptance data.

Moreover, the appropriate lens design for a wearer determining device comprises a processor for executing the computer executable instructions.

The computer executable instructions comprise instructions for determining an appropriate lens design for a wearer based on the levels of acceptance data.

The invention has been described above with the aid of embodiments without limitation of the general inventive concept.

Claim 1:
Method implemented by computer means for determining the most appropriate lens design for a wearer for the purpose of providing a lens to the wearer, the method comprising:
- a level of acceptance determination step S22 during which the levels of acceptance of the user for multiple lens designs are determined according to a method comprising:
o a notation table receiving step S6 during which a notation table of the user is received, the notation table corresponding to a set of subjective values representing the sensitivity of the user to a set of optical aberrations;
o a notation table associating step S10 during which the notation table of the user is associated to a lens design based on the set of optical aberrations; and
o a level of acceptance determining step S12 during which the level of acceptance of the user for the lens design is determined based on the association of the notation table of the user and the lens design;
- a comparison step S26 during which the levels of acceptance of the multiple lens designs are compared together; and
- a lens design determining step S28 during which the most appropriate lens design for the wearer is determined,
characterized in that
the method further comprises prior to the notation table associating step, a zone defining step S8 during which zones are defined on a lens design map, and wherein the notation table associating step and the level of acceptance determining step are carried out for each defined zone; and
comprising prior to the comparison step S26 a zone defining step S23 during which zones corresponding to each level of acceptance are defined on the design maps and a level of satisfaction determining step S24 during which a level of satisfaction is determined.