阅读说明：本技术 分析个体视野的方法以及相应的眼科镜片 (Method for analyzing the visual field of an individual and corresponding ophthalmic lens ) 是由 J-A·萨赫尔 A·阿里欧 A-C·施尔伦 D·崔瓦兹-伯那丁 于 2017-12-21 设计创作，主要内容包括：一种分析个体视野的方法,所述方法包括以下步骤：-当所述个体执行第一任务时,针对所述个体的第一组眼位参数来测量(S4)所述个体的第一视野(VF1)；-当所述个体执行附加任务时,针对所述个体的附加的一组所述眼位参数来测量(S6)所述个体的至少一个附加视野(VFi)；-基于所述第一视野(VF1)和所述至少一个附加视野(VFi)来确定(S8)功能性视觉空间,所述功能性视觉空间是对所述第一视野和所述至少一个附加视野的包络。所述附加任务不同于所述第一任务和/或所述附加的一组眼位参数不同于所述第一组眼位参数。还提出了一种相应的眼科镜片。(A method of analyzing the visual field of an individual, the method comprising the steps of: -measuring (S4) a first field of view (VF1) of the individual for a first set of eye position parameters of the individual when the individual performs a first task; -measuring (S6) at least one additional field of View (VFi) of the individual for an additional set of the eye position parameters of the individual when the individual performs an additional task; -determining (S8) a functional visual space based on the first field of view (VF1) and the at least one additional field of View (VFi), the functional visual space being an envelope of the first field of view and the at least one additional field of view. The additional task is different from the first task and/or the additional set of eye parameters is different from the first set of eye parameters. A corresponding ophthalmic lens is also presented.)

1. A method of analyzing a visual field of an individual, the method comprising the steps of:

-measuring (S4) a first field of view (VF1) of the individual for a first set of eye position parameters of the individual when the individual performs a first task;

-measuring (S6) at least one additional field of View (VFi) of the individual for an additional set of eye position parameters of the individual, while the individual performs an additional task;

-determining (S8) a functional visual space based on the first field of view (VF1) and the at least one additional field of View (VFi), the functional visual space being an envelope of the first field of view and the at least one additional field of view;

wherein the additional task is different from the first task or the additional set of eye parameters is different from the first set of eye parameters.

2. The method of claim 1, wherein the first or the additional field of view (VF 1; VFi) is defined by a base surface (B1; B2; B3) of a viewing cone (C1; C2; C3), wherein the viewing cone (C1; C2; C3) comprises a vertex located on an eye of the individual and the viewing cone (C1; C2; C3) comprises a height defined by a task performed by the individual.

3. The method according to claim 1 or 2, wherein the functional visual space is defined by a volume join between the measured fields of view (VF1, VFi).

4. The method according to any one of claims 1 to 3, wherein the first field of view (VF1) includes a temporal component.

5. The method of any of claims 1-4, wherein the eye position parameters include parameters defining:

the eye orientation of the individual, or

Temporal evolution of the individual's eye orientation, or

Orientation of the individual's head, or

Temporal evolution of the individual's head orientation, or

The posture of the individual, or

A temporal evolution of the posture of the individual.

6. The method according to claim 5, wherein during the measuring step a device (4) for detecting the orientation of the individual's eyes is used.

7. The method according to claim 5 or 6, wherein during the measuring step a device (26) for detecting the orientation of the individual's head is used.

8. The method according to any one of claims 5 to 7, wherein during the measuring step, a device (26) for detecting the posture of the individual is used.

9. The method of any of claims 1-8, wherein the measuring step comprises displaying a stimulus intended for the individual.

10. The method of claim 9, wherein the order of display is determined based on the tasks to be tested.

11. The method according to any one of claims 1 to 10, wherein the functional visual space is further defined by a plurality of weights respectively associated with the measured fields of view (VF1, VFi).

12. The method according to any one of claims 1 to 11, comprising the step of determining a lens design based on the determined functional visual space.

13. The method according to any one of claims 1 to 12, comprising the step of selecting a training program based on the determined functional visual space.

14. The method according to any one of claims 1 to 13, comprising the step of selecting a visuospatial re-education protocol based on the determined functional visual space.

15. An ophthalmic lens intended to be worn by an individual, wherein said lens has a design determined on the basis of a functional visual space determined according to the method of one of claims 1 to 11.

Technical Field

The present invention relates to a system for testing vision.

More precisely, the invention relates to a method for analyzing the visual field of an individual and to a corresponding ophthalmic lens.

Background

It is known to measure an individual's useful field of view (UFOV) by testing his/her response to stimuli displayed on a screen.

The useful field of view of this measurement is intended to mean the area where the individual is able to locate the stimulus without moving the head or eyes.

Thus, such tests are performed for a given posture of an individual who is typically sitting in front of the screen, and for a given line of sight (i.e. gaze orientation).

This particular measurement condition is quite different from the conditions that an individual may encounter in daily life.

As a result, the useful field of vision defined above may appear to be insufficient to understand the actual needs of an individual, for example when defining an ophthalmic lens that is best suited to correct an individual's ametropia.

Disclosure of Invention

In this context, the present invention provides a method of analyzing the visual field of an individual, the method comprising the steps of:

-measuring a first visual field of the individual for a first set of eye position parameters of the individual when the individual performs a first task;

-measuring at least one additional field of view of the individual for an additional set of the eye position parameters of the individual when the individual performs an additional task;

-determining a functional visual space based on the first field of view and the at least one additional field of view, the functional visual space being an envelope of the first field of view and the at least one additional field of view;

wherein the additional task is different from the first task and/or the additional set of eye parameters is different from the first set of eye parameters.

Thus, this functional visual space gives a representation of the field of view, which illustrates several postures or several tasks that an individual may influence in daily life. Thus, the functional visual space can be advantageously used when seeking optical solutions that provide a field of vision that is best suited for an individual in daily life.

The proposed method may further comprise any of the following features:

-the first field of view or the additional field of view is defined by a base surface of a viewing cone;

-the viewing cone comprises an apex located on the eye of the individual;

-the viewing cone comprises a height defined by a task performed by the individual;

-the functional visual space is defined by volume ties between the measured fields of view;

-the first field of view and/or the second field of view comprises a temporal component;

-the eye position parameters comprise parameters defining: an eye orientation of the individual, or a temporal evolution of an eye orientation of the individual, or a head orientation of the individual, or a temporal evolution of a head orientation of the individual, or a posture of the individual, or a temporal evolution of a posture of the individual;

-during the measuring step, using means for detecting the orientation of the individual's eye;

-during the measuring step, using means for detecting the orientation of the individual's head;

-during the measuring step, using means for detecting the posture of the individual;

-the measuring step comprises displaying the stimulus intended for the individual, for example using a screen;

-determining (e.g. on screen) the order of display based on the task to be tested;

-the functional visual space is further defined by a plurality of weights respectively associated with the measured fields of view;

-the method comprises the step of determining a lens design based on the determined functional visual space;

-the method comprises the step of selecting a training program based on the determined functional visual space;

-the method comprises the step of selecting a visual-spatial re-education protocol based on the determined functional visual space;

-the method comprises assessing the effect of an ophthalmic treatment based on the determined functional visual space.

The invention also provides an ophthalmic lens intended to be worn by an individual, wherein said lens has a design determined on the basis of the functional visual space determined by the method set forth above.

Drawings

The invention will be better understood from the accompanying drawings, in which:

figure 1 illustrates the main steps of implementing the method of the invention;

figure 2 schematically shows a possible representation of the field of view of the measurement;

figure 3 illustrates the main steps of a possible method for measuring the field of view;

figure 4 schematically shows a possible system for measuring the field of view; and

fig. 5 schematically shows another possible system for measuring the field of view.

Detailed Description

Figure 1 shows the main steps of a method of analyzing the field of view of an individual.

The method starts in step S2: the characteristics of the visual test to be performed are determined as a function of the target task, the eye/head/body coordinates associated with the target task, and parameters relating to the individual conducting the visual test.

The target task is generally a task performed in daily life, such as reading, walking, and the like.

For example, in step S2, parameters defining the visual stimuli presented to the individual may be determined according to the target task (as explained further below). This is because an individual tends to use his/her visual abilities in different ways depending on the tasks in daily life he/she is performing.

These parameters defining the visual stimulus may include:

the type of stimulus to be identified (e.g. one or several of the following: grid, letter, symbol, face, scene, object);

characteristics of the stimulus (e.g. one or several of size, spatial frequency or acuity, contrast, motion, orientation, colour, brightness);

-location(s) in the field of view: center, near center, periphery, lower view, upper view, left, right (several locations may be used together to characterize an assigned attention);

-the number of stimuli;

whether the field includes noise (field noise makes it possible to characterize selective attention);

the focal plane of the stimulus (e.g. one or several of: distance, middle, near, another distance).

Several stimuli or objects may be presented simultaneously and each stimulus or object may then be defined according to one or several of these parameters listed above.

The test to be performed is also defined by eye/head/body coordinates to be considered according to the target task.

The eye/head/body coordinates define the corresponding positions of the eyes, head and body.

Visual testing may be performed under several different possible conditions, such as:

-a fixed straight state;

a fixed offset state (e.g. defined by the position and magnitude of the offset compared to the straight state and/or defined using an angle specifying the relevant direction relative to the straight state);

a movement state (e.g. defined by a starting position, direction, speed, movement amplitude and movement type relative to a straight state).

It may be noted that for each state, the position of the eyes, the position of the head and the position of the body are defined and may additionally be moving (for the moving state).

As described above, in step S2, characteristics of the vision test are also determined based on parameters relating to the individual performing the test, such as:

whether the individual is wearing optical correction, and possibly the type of correction (e.g. spherical or progressive lens);

-quality of binocular vision;

cognitive skills (e.g. determined using the easy mental state scale);

-refractive error of the individual;

age of the individual (e.g. the moment and/or duration of stimulus presentation is adapted according to age of the individual, since the reaction time is longer for elderly);

motor skills (eye movement, head and/or body movement, body trunk coordination features).

Eye movement may be characterized, for example, by one or several of the following parameters: gaze stability, gaze shift, nystagmus, gaze parallax, convergence, eye jump amplitude, following, convergence and divergence of extraocular muscles.

Head and body motion may be characterized, for example, by one or several of the following parameters: tremor (parkinsonism), postural stability, loss of balance, walking speed.

Body trunk coordination may be characterized, for example, by one or several of the following parameters: the number of segments involved, their stiffness, the amplitude and speed of their motion.

Then, the method of fig. 1 includes step S4: the (part of the) test defined according to step S2 above is used to measure the individual' S first field of view VF 1.

This measurement is performed for a first set of eye position parameters of the individual when the individual performs a first task, such as a daily life task as explained above.

An example of how this measurement may be achieved is described below with reference to fig. 3.

The method of fig. 1 further includes step S6: as the individual performs additional tasks, additional visual fields VFi of the individual are measured for an additional set of eye position parameters.

The additional task is different from the first task and/or the additional set of eye parameters is different from the first set of eye parameters.

Several different measurements may be performed on such additional fields of view VFi, each time using different eye position parameters and/or when performing different tasks.

An example of how each of these additional measurements may be implemented is described below with reference to fig. 3.

Can extend in space through a solid angle, or indeed through two angles theta defining the angles of the measured field of view in two orthogonal directions (e.g. horizontal and vertical), respectively_x、θ_yTo define the field of view of the measurement (here the first field of view VF1 or the additional field of view VFi).

The measured field of view may also be defined by a volume, e.g., a cone whose apex is located on an individual's eye and whose height z corresponds to the task performed by the individual (e.g., height z is equal to the distance for distance, mid-view, or near-view test vision as described above).

In a possible embodiment, the volume defining the field of view of the measurement may be defined by a plurality of frustoconical portions, as schematically shown in fig. 2, joining the corresponding bases B1, B2, B3 of the just mentioned several viewing cones C1, C2, C3.

In this example, cone C1 corresponds to near, cone C2 corresponds to mid, and cone C3 corresponds to far.

Several visual types are contemplated so that how the individual's visual and attentional abilities evolve can be characterized in terms of the distance(s) and activities (or tasks) involved with the individual. In this respect it may be noted that even when an individual is gazing at a certain distance in a certain gaze direction (e.g. looking at the road in front of him when driving), he/she may react to stimuli in other gaze directions and/or at another distance (e.g. inside the vehicle, e.g. on the dashboard).

The field of view of the measurement may also include a temporal component. For example, in practice, the spatial composition of the field of view (represented by a solid angle or volume as explained above) may be determined for several time points, thereby describing the individual's visual and cognitive processing times.

The measured field of view may also include an indication of a threshold for distinguishing between stimuli. This threshold can be determined by showing different degrees of stimulation. Indeed, a threshold may be indicated for each of a plurality of directions within the field of view. However, according to a possible embodiment, such threshold indications are not included in the measured field of view, but rather the degree (or size) of the displayed stimuli is determined based on the skill of the individual and/or based on the measured activity.

After measuring several fields of view VF1, VFi as just described, the method of fig. 1 comprises a step S8: a functional visual space is determined based on the first field of view VF1 and the additional field of view(s) VFi.

The functional visual space considered here is defined as the envelope to the first field of view and the additional field(s), i.e. the set of points contained in any of the first field of view and the additional field(s).

In practice, the functional visual space may be determined as a volumetric junction between the first field of view VF1 and each of the additional field of view(s) VFi.

Depending on the possible implementation, different weights may be attributed to the respective measured fields of view VF1, VFi (e.g., depending on the eye position parameters or tasks involved for measuring the relevant fields of view VF1, VFi as compared to the target eye position parameters or tasks) to further define the functional visual space.

The method of fig. 1 then comprises step S10: the solution is selected based on the determined functional visual space, i.e. actually based on the parameters or data characterizing the functional visual space determined in step S8.

Selecting a solution may include determining an optical article to be worn by the individual having undergone the above-described test.

Selecting a solution may, for example, comprise determining a lens design based on the determined functional visual space.

In particular, the design of a Progressive Addition Lens (PAL) may be determined based on the determined functional visual space.

By defining the individual field of vision for one or more tasks encountered in daily life (an object distance is associated with each relevant task), the functional vision space can be used to determine where on the progressive addition lens the area providing correction should be located and, possibly, where on the progressive addition lens the corresponding correction corresponding to the respective considered object distance (e.g. correction for near vision or correction for in-view vision or correction for far vision) should be provided.

Selecting a solution may also include determining a design of a filter to be deposited on a lens to be worn by an individual.

Such a filter may be deposited in accordance with the determined functional vision space in an area of the lens corresponding to an area where spatial optical noise (such as may be produced by a progressive addition lens) would reduce the visual ability of the individual (in which case the spatial and/or temporal component of the functional vision space includes, for example, data indicative of an individual's adverse reactions during a test involving spatial noise).

Selecting a solution may include selecting a training plan based on the determined functional visual space. Such a training program may then be presented to the individual to improve his/her visual ability, particularly in terms of the field of vision.

In particular, the determined functional visual space may be used to at least select an appropriate visual-spatial re-education protocol.

Such a visual-spatial re-education protocol may, for example, aim to optimize the eye/head/body coordinates of an individual to compensate for field loss and/or to improve the individual's ability to extract relevant visual information to find his/her spatial road.

Selecting a visuospatial re-education protocol may also involve quantifying the impact of eye/head/body coordinates on the resulting useful field of view (to select a re-education protocol intended to improve this coordinate in the event of a negative impact).

In this object, the functional visual space can be determined as explained above under various different conditions involving more or less degrees of freedom of the eye/head/body coordinates, so that the influence of the eye/head/body coordinates can be evaluated and, possibly, a re-education protocol aimed at improving the eye/head/body coordinates can be proposed to the individual.

According to another possible embodiment, the determined functional visual space may be used for evaluation and follow-up of ophthalmic treatments.

This is the case, for example, when the individual is a patient suffering from a vision condition such as age-related macular degeneration or glaucoma.

Visual conditions may indeed lead to loss of visual acuity, loss of sensitivity to contrast, loss of ocular visual line stability, loss of visual field range.

Such disabilities then have an impact on performance in moving eye exploration and recognition, reading, spatial orientation and navigation, facial recognition, etc.

In view of this, it may be advantageous to determine a functional visual space prior to and/or throughout an ophthalmic treatment intended to treat a related visual condition.

In particular, the above-mentioned determination of the functional field of view (including before the start of the ophthalmic treatment) makes it possible to:

-assessing the effect of visual disorders on the data obtained from the assessment of functional vision field;

-comparing these data with corresponding data obtained for healthy subjects in order to assess the degree of disability;

-assessing the effect of the ophthalmic treatment by re-determining the functional visual space (e.g. at some specific step of the treatment);

-directing a further ophthalmic treatment (i.e. selecting a further step of the ophthalmic treatment or another ophthalmic treatment) or selecting a visual-spatial re-education plan or protocol (as mentioned above) based on the data defining the functional visual space, possibly in order to obtain a target value for the functional visual space.

Fig. 3 shows the main steps of the method for measuring the field of view. This method is described below as possibly being implemented in two different systems for measuring the field of view (shown in fig. 4 and 5, respectively).

A first possible system for measuring the field of view is shown in fig. 4, which system comprises a display screen 2, a (video) camera 4 directed to the face of the individual, a user interface 6, such as a joystick, a keyboard or a touch screen, means 8 for bringing the head or body torso of the individual into a certain position, such as a chin rest, and a control unit 10.

The display screen 2 may be used to display stimuli intended for the individual, as explained further below.

The camera 4 may be used as an eye tracker, i.e. as a means for detecting the eye orientation (or gaze direction) of an individual.

A second possible system for measuring the field of view is a user experience room 20, as schematically shown in fig. 5. This user experience room 20 comprises a screen 22, a projection unit 24 adapted to project images onto the screen 22, and sensors 26 attached to respective head or body parts of the individual, respectively.

The sensor 26 thus forms a means for detecting the posture of the individual.

As an alternative to these two possible systems, an augmented reality headset may be used, possibly comprising an eye tracker and a unit adapted to determine the position and/or orientation of the headset (such as an accelerometer and/or a gyroscope). Thus, this unit is adapted to detect the head orientation of the individual when the individual is wearing the head-mounted device.

The method of fig. 3 includes step S12: an individual is presented with a visual stimulus that includes one of several targets to be recognized by the individual.

The stimulus is presented (under control of a control unit such as control unit 10) for example by being displayed on a screen (such as display screen 2 of fig. 4 or screen 22 of fig. 5) or, alternatively, in an augmented reality headset as described above.

The type of stimulus to be displayed, its presentation (display) timing, and its presentation (display) duration are determined according to the above-described step S2.

In particular, the order of the stimuli to be displayed on the screen may be determined based on the task to be tested.

In step S14, feedback of the individual on the stimulus presented to him/her is obtained, for example, by a user interface (such as user interface 6 of fig. 4) or by detecting a specific movement of the individual (e.g., at least one of sensors 26 of fig. 5).

Feedback of the individual is received by a control unit (such as control unit 10 of fig. 4) that determines the individual's ability to react to a particular stimulus (e.g., identify a particular target in the presented stimulus).

Thus, the control unit (e.g. the control unit 10) is adapted to assess the visual field of the individual at step S16 (in practice after repeating the presenting stimulus of step S12 several times and receiving the respective feedback from the individual according to step S14 several times).

The visual field may be measured by the method of fig. 3 just described for a given set of eye position parameters, possibly while the individual performs a particular task.

These eye position parameters may include parameters that define:

-the eye orientation of the individual, and/or

-temporal evolution of the eye orientation of the individual, and/or

-head orientation of the individual, and/or

-temporal evolution of the individual's head orientation, and/or

-the posture of the individual, and/or

-a temporal evolution of the posture of the individual.

Each eye position parameter considered may be fixed by the conditions under which the test is performed (e.g. using chin rest 8 of fig. 4), or may be measured in real time during the test, for example using an eye tracker for determining the gaze direction (by means of camera 4 in the embodiment of fig. 4 or in an augmented reality headset of the above-proposed variant) or using sensor 26 in the embodiment of fig. 5 for measuring the position and/or movement of the head or body torso.

Thus, the above-described control unit (e.g., control unit 10 in the context of fig. 4) may actually record (i.e., store in memory) the measured eye position parameters as just mentioned in association with the measured field of view.