CN107106002B

CN107106002B - Apparatus for measuring heterophoria and method for measuring heterophoria using the same

Info

Publication number: CN107106002B
Application number: CN201480084311.9A
Authority: CN
Inventors: 保金华; 布约恩·德罗贝; 余新平; 苏彬彬; 吴戈; 陈浩
Original assignee: Shanghai Essilor Optical Co ltd; Wenzhou Medical University; Essilor International Group Optical Corp
Current assignee: Shanghai Essilor Optical Co ltd; Wenzhou Medical University; Essilor International Group Optical Corp
Priority date: 2014-12-25
Filing date: 2014-12-25
Publication date: 2020-07-28
Anticipated expiration: 2034-12-25
Also published as: WO2016101204A1; CN107106002A

Abstract

The present invention provides an apparatus for measuring heterophoria, the apparatus comprising: a front side (1) comprising an opening (11) corresponding to a position of an eye of the subject; a rear side (2) parallel to the front side (1) and presenting a visual display pattern (21) arranged towards the front side (1) and configured to be used in a heterophoria measurement; and an optical device (5) comprising at least one set of lenses having different powers corresponding to different accommodation needs of the subject, wherein the optical device (5) is positioned to correspond to the opening (11) and in front of at least one eye of the subject such that the visual display pattern (21) is adapted to be viewed by the subject through the optical device (5). The device provides an inexpensive, simple, fast and accurate way to measure heterophoria at different adjustment values.

Description

Apparatus for measuring heterophoria and method for measuring heterophoria using the same

Technical Field

The present invention relates generally to optometry tools, and in particular to an apparatus for measuring heterophoria. Furthermore, the invention relates to a method for measuring heterophoria using the device.

Background

Phoropter generally refers to the measurement of monocular parameters such as myopia, hyperopia, astigmatism, and presbyopia. However, in order to obtain a comprehensive prescription, it is also necessary to measure binocular vision values, in particular heterophoria (heterophoria), which can be used for advanced and personalized spectacle prescriptions, such as for determining the under-addition value of an ophthalmic progressive lens.

Specifically, phoria is an eye state in which the directions in which the eyes point in the rest position do not coincide with each other when binocular fusion is not performed. A person with two normal eyes (usually) has a single vision due to the combined use of a sensory and motor fusion system. The effect of the kinematic fusion system is to point both eyes at the object of interest, visually detecting any offset (and the kinematic system correcting). Only when eye fusion is not present, phoria will occur when the left and right eyes are separated. If a person covers one eye (e.g., with his/her hand), sensory information about the position of the eye on the track can be removed. Without this, there is no stimulus for binocular fusion, and the eyes move to a "rest" position. The difference between this position and the position where the eyes are not covered is heterophoria.

Heterophoria can be found on almost everyone, only to a different extent and depending on the situation. Heterophoria is usually asymptomatic. This is when it is said to be "compensated" for. When a fused reserve is used to compensate for an anticline, it is known to compensate for vergence. In severe cases, signs and symptoms appear when the fusion vergence fails to overcome the cryptoplasia. This is known as decompensated strabismus, which leads to eye fatigue. Furthermore, heterophoria may lead to a partial or also called strabismus.

There are many optometric measurements/tests well known in the art, such as Von Graefe, modified Thorington test, Howell test, madoks rod, etc., to measure the value of heterophoria. In general, these measurements/tests can be classified into the following two categories:

direct reading of the value of heterophoria by the subject (the subject himself sees the value of his heterophoria and reports to the examiner, such as the modified Thorington test); and

the scotopic readings are taken by the examiner (the examiner determines the scotopic value, but not the subject, e.g. von graeffe).

The phoria test can be performed at any distance, but the phoria value varies with the measured distance.

In addition, different accommodation values can be measured by moving the plane of the target or by adding a positive or negative lens in front of the subject's eye. This requires a complex optometry instrument or set of test mirrors (both of which are expensive) and requires experienced inspection personnel for use. For near vision, the heterophoria test must be manually placed at the correct distance. This can lead to experimental error due to the use of trial frames, as the test is usually held by the subject and cannot be placed at precise distances.

In this respect, determining the near-phoria under different adjustment conditions requires complex and expensive equipment (phoropter, trial frame) and skilled personnel using them. However, the measurement/testing in the art lacks accuracy because the distance to the near target is not fixed (each time adjusted by the operator). Moreover, measuring heterophoria is time consuming due to lens replacement, especially with trial frames.

Disclosure of Invention

To this end, the object of the present invention is to provide a device for measuring heterophoria (such as near heterophoria) at a fixed and precise distance and under different adjustment conditions, in order to overcome the above-mentioned drawbacks.

The apparatus for measuring phoria of a subject comprises:

-an anterior side comprising an opening corresponding to a position of the eye of the subject;

-a rear side parallel to the front side and presenting a visual display pattern disposed towards the front side and configured to be used in a heterophoria measurement;

the apparatus further comprises an optical device comprising at least one set of lenses having different powers corresponding to different accommodation needs of the subject, wherein the optical device is positioned to correspond to the opening and in front of at least one eye of the subject such that the visual display pattern is adapted to be viewed by the subject through the optical device.

In various embodiments of the invention, one or more of the following arrangements may be used:

-the visual display pattern is adapted to be adjusted;

-the optical device comprises two sets of lenses positioned in front of the eyes of the subject, respectively, and both sets comprise the same lenses, wherein the order of the lenses on the two sets is configured to be reversed in order to mitigate binocular rotation. Preferably, the distance between the optical centers of the lenses is adjustable when using said two sets of lenses, so as to correspond to the pupil distance of the subject, so as to be aligned with the visual axis of the subject;

-the optical device comprises a null position in which no lens or lens of zero power (0.00D) is positioned and no lens is seen by the subject;

the number of lenses in said at least one set of lenses is limited, for example limited to five lenses, the powers of these lenses being for example +1.00D, +1.50D, +2.00D, +2,50D, + 3.00D. Preferably, the power value of one lens of the at least one set of lenses is zero diopters;

-the device comprises a variable prism positioned corresponding to the opening and in front of at least one eye of the subject and changing the visual display pattern for use in the fusion amplitude measurement;

the device comprises at least one specific lens, for example a Maddox filter or a vertical prism, positioned in correspondence to the opening to assist the heterophoria measurement;

-the device further comprises an indicator adapted to be adjusted by the subject to indicate a scotopic value obtained by the subject.

-the device further comprises a storage unit that records the phoria value for each lens and sends the recorded phoria values to a computer system that sends the values to a database for further analysis;

the device is mainly made of translucent plastic; and is

-the apparatus further comprises a padded forehead headrest positioned on the front side for receiving the forehead of the subject.

Thus, the apparatus according to the invention may facilitate, due to the apparatus configuration, the phoria measurement under the adjustment conditions provided by the lens arrangement and at a fixed measurement distance, and provide more accurate measurement results without the need for expensive equipment in the field and experienced inspectors using such equipment.

A second aspect of the invention provides a method for measuring heterophoria of a subject by using the device. The method comprises the following steps:

providing a visual display pattern at the rear side;

adjusting the distance between the front side and the rear side;

setting an initial power of the optical device;

presenting the visual display pattern for viewing through the optical device by at least one eye of the subject;

recording an identification of the parameter of the phoria measurement observed by the subject;

repeating steps c to e until a limited number of powers of the optical device have been tested.

Alternatively, step e further comprises the step of memorizing the identity by means of a memory unit.

Thanks to the above features, the invention provides a cheap, simple, fast and accurate apparatus and method for measuring heterophoria, in particular near heterophoria, at different adjustment values (different add-ons). At the same time, the efficacy of measuring heterophoria is improved compared to the measurement devices and methods of the art.

Drawings

Further characteristics and advantages of the invention will emerge from the description of the following embodiments of the invention, given as non-limiting examples, with reference to the figures listed below.

Figure 1 is a perspective view of a device for measuring heterophoria according to a first embodiment;

FIG. 2 is a perspective view of the apparatus of FIG. 1 without the optical device;

FIG. 3 is a front view of the optics of the apparatus in FIG. 1;

FIG. 4 is an enlarged front view of a visual display pattern of the test for heterophoria of the device in FIG. 1;

fig. 5 is a perspective view of a device for measuring heterophoria according to a second embodiment;

FIG. 6 is a perspective view of the apparatus of FIG. 5 without the optical device, showing the heterophoria test side;

FIG. 7 is a perspective view of the apparatus of FIG. 5 without the optical device, showing the fused amplitude test side;

figures 8 and 9 are front views of the optics of the device in figure 5;

fig. 10 is an enlarged front view of a visual display pattern for the fusion amplitude test of the device in fig. 5.

Detailed Description

It is to be understood that the drawings are not necessarily to scale, presenting a simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the invention disclosed herein (including, for example, specific dimensions, orientations, locations, and shapes) will depend to some extent on the particular intended application and use environment.

The invention has been described with reference to the embodiments and the accompanying drawings. In the drawings, the same reference numbers are used to identify the same or similar items.

Fig. 1 to 4 show a first embodiment of the device according to the invention. This embodiment is a simple version comprising a rectangular box and an optical device 5 attached to the rectangular box for measuring horizontal heterophoria under different adjustment conditions.

In particular, the rectangular box comprises a front side 1 and a rear side 2 parallel to the front side 1.

The front side 1 comprises two

openings

11, 13 as shown in fig. 2, which correspond to the positions of the left and right eyes of a subject whose scotopic oblique values are intended to be tested. Preferably, on the bottom edge of the front side 1, there is a recess 16 for receiving the nose of the subject.

In addition, the distance between the two

openings

11, 13 is adapted to be adjusted for different subjects, and in this embodiment corresponds to a pupillary distance of the subject ranging from 55mm to 65mm, preferably 60 mm.

The rear side 2 is opposite the front side 1 and is located at the other end of the cassette. The visual display pattern 21 is arranged on the rear side 2, towards the front side 1. The visual display pattern 21 is an indication of the phoria value for a phoria test, such as the modified Thorington test, which is printed on paper or plastic and can be varied and adjusted according to different phoria measurements, e.g. von graeffe, the modified Thorington test, the Howell test, the maduox stick, etc.

The visual display pattern 21 further comprises a light source 23 for phoria measurement as shown in fig. 4, such as an L ED light, and a battery and switch (not shown) fixed to the rear side of the device for turning the light on and off.

The front side 1 and the rear side 2 are connected by two

side connecting parts

3, 4, the length of which can be adjusted by an adjusting device (e.g. a telescopic rod) according to the measurement requirements (e.g. 33cm) and can be temporarily fixed during the measurement.

The optical device in the form of wheel 5 comprises a set of lenses on the periphery of the wheel, as shown in fig. 3, and these lenses are limited in number (e.g. six), having different powers corresponding to different adjustment needs of the subject, such as +1.00D, +1.50D, +2.00D, +2,50D, +3.00D, 0.00D (or no lenses, empty position).

The wheel further comprises an aperture 51 at its center, corresponding to the mounting point 15 on the left side of the front side 1, for attachment to the front side by means of screws, bolts or the like, for rotatable mounting on the front side, wherein at least one lens (or empty position) covers the left side opening 11.

Advantageously, the rectangular box is made of frosted polycarbonate to ensure a light weight, the wheels 5 are made of the same material and the lenses are made of transparent polycarbonate.

In this embodiment, when the wheel 5 is rotated, a change in accommodation is produced only for one eye on the left eye, and the right eye uses the madoks rod 131 positioned on the right-side opening 13, as shown in fig. 1.

According to this first embodiment, the apparatus can be used to measure horizontal phoria under different adjustment conditions by:

1. the wheel 5 is set to a no power lens or an empty position in which no lens is provided for the subject's left eye.

2. The subject is asked to look through an opening in the device and to fix the light in the centre of the scale. With his left eye he will see the scale and light, and with his right eye he will see a vertical line due to the madoks rod.

3. The task is to read on which scale the vertical line lies (the value of its phoria without multifocal lenses) and report it to the inspector.

4. The wheel 5 turns to a multifocal lens, wherein one of the following three modes can be adapted: (1) degree increase: +1D, +1.5D, +2D, and the like; (2) degree reduction: +3D, +2.5D, and the like; (3) and (4) random sequence.

5. Repeat steps 2, 3 and 4 and write down values until all lenses (or a limited number of lenses, at the discretion of the inspector) have been tested.

Alternatively, step 1 can also be started with different powers. However, it is preferred to start the measurement with a sub-zero plus light or empty position.

Thus, the values obtained with the device are the horizontal phoria values under different adjustment conditions, which can be used, for example, to determine a personalized under-fill value prescribed, for example, for progressive multifocal lenses, bifocal lenses or reading with single-vision lenses.

Furthermore, the device may further comprise an indicator (not shown) adapted to be adjusted by the subject to indicate the phoria value obtained by the subject.

Moreover, the apparatus may further comprise a storage unit that records the phoria value of each test lens. Such recorded values may be sent to a database of a computer or cloud system that further analyzes the data for further processing, such as determining personalized under-lighting values for the subject (e.g., child or adolescent).

Fig. 5 to 10 show a second embodiment of the device according to the invention. This is a more complex version. It changes accommodation for binocular (both left and right eye) phoria measurement and preferably can be reversed to measure fusion amplitude without any accommodation.

This second embodiment comprises a rectangular box, two

optical devices

5L, 5R attached to the rectangular box for binocular measuring the phoria values under different adjustment conditions, and a lisley prism system for fusion amplitude testing.

In particular, the rectangular box comprises a front side 1, a back side 6 parallel to the front side, and a back side 2 positioned between the front side 1 and the back side 6 and also parallel to the front side 1.

The front side 1 comprises two

openings

11, 13 as shown in fig. 6, which correspond to the positions of the left and right eyes of the subject whose scotopic oblique values are intended to be tested. Preferably, on the bottom edge of the front side 1, there is a recess 16 for receiving the nose of the subject.

In addition, the distance between the two

openings

11, 13 is adapted to be adjusted for different subjects, and in this embodiment corresponds to a pupillary distance of said subject ranging from 55mm to 65mm, preferably 60 mm.

The back side 6 is opposite the front side and is located at the other end of the cartridge. The back side 6 further comprises two

openings

61, 63 as shown in fig. 7, which correspond to the positions of the left and right eyes of the subject whose fused amplitude values are intended to be tested. Preferably, on the bottom edge of the dorsal side 6, there is another recess 66 for receiving the nose of the subject.

The back side 2 is arranged between the front side 1 and the back side 6 and is located in the box. The visual display device is arranged on the rear side 2, wherein the visual display pattern 21 for the oblique values faces the front side 1 and the visual display pattern 22 for the fused amplitude values faces the rear side 6.

The visual display means is for example an L CD or O L ED display presenting a visual display pattern 21 for a phoria test (e.g. for the modified Thorington test) and a visual display pattern 22 for a fusion magnitude (e.g. a rectangular letter bus).

The front side 1 and the back side 6 are connected by two

side connecting members

3, 4 having a fixed length, and the back side 2 is attached to the two connecting members and adapted to slide thereon, such that the distance d1 between the front side 1 and the back side 2 and the distance d2 between the back side 6 and the back side 2 can be adjusted as desired, for example between 0cm and 40 cm.

In addition, the visual display device can automatically adjust the display pattern according to the distance d1 and/or d2 so that the scale of the heterophoria test always corresponds to 1 prism diopter, and so that the size of the letter of fusion amplitude always equals 6/10. In this respect, advantageously, the distance d1 or d2 is measured electronically and used to automatically display the correct scale and angular size.

Referring to fig. 4 and 10, for example, for phoria measurement, the size of 1 scale is equal to 1 prism diopter, width (in mm) is distance d1(mm)/100, wherein the distance d1 is provided by electronic measurement and fed back to the display device, for fusion amplitude measurement, the letter size shown in fig. 10 is 1 letter angular size 6/10, i.e., 8.33 arc minutes, the letter size (mm) is tan (8.3 arc minutes) ×, distance d2 (mm).

The optical device is in the form of two

wheels

5L, 5R, and each wheel includes a set of lenses on the periphery of the wheel, as shown in fig. 8 and 9, and these lenses are limited in number (e.g. six), having different powers corresponding to different accommodation needs of the subject, such as +1.00D, +1.50D, +2.00D, +2,50D, +3.00D, 0.00D (or no lenses, empty positions).

The wheels include apertures 51L/51R, respectively, in the center of the wheels, corresponding to the two mounting

points

15L, 15R on the left and right sides of the front side 1 for attachment thereto by screws, bolts, etc. for rotatably mounting on the front side where at least one lens (or empty position) of the wheel 51L covers the left opening 11 and at least one lens (or empty position) of the wheel 51R covers the right opening 13.

The form of the lisley prism system used for the fusion amplitude test is a horizontal lisley prism positioned over the

openings

61, 63 of the two eyes of the subject. The distance between the two risley prisms is adapted to be adjusted by an adjustment means 68, such as an adjustment wheel, to align with the visual axis of the subject.

Similarly, the rectangular box is made of frosted polycarbonate to ensure a light weight, the two wheels are made of the same material, preferably polycarbonate, and the lens is made of transparent polycarbonate.

Thus, the second embodiment comprises two working sides: the heterophoria side, where the subject faces the front side and looks through the

openings

11, 13 for heterophoria measurement, and the fusion amplitude side, where the subject faces the back side and looks through the

openings

61, 63 for fusion amplitude measurement.

Due to the above arrangement, the optical device can change the binocular adjustment during a phoria measurement, while no adjustment is required during a fusion amplitude measurement.

In this embodiment, when the

wheels

5L, 5R are rotated, both the left and right eyes produce binocular accommodation change, and the right eye also uses the madoks rod 131 positioned on the right side opening 13, as shown in fig. 7.

When the device is used for phoria measurement, the subject faces the anterior side 1 and is viewed through two

wheels

5L, 5R, and the phoria value of the subject is measured by:

1. the distance d1 of the display device on the rear side (which may be, for example, the usual working distance at close proximity) is adjusted according to the decision of the inspector. The device can automatically change the scale size on the display means to this distance accordingly, i.e. so that 1 scale equals one prism diopter.

2. The wheels are set to a neutral power lens or an empty position.

3. The subject is asked to look through the

openings

11, 13 in the device and to fix the light in the centre of the scale. With his left eye he will see the scale and light, and with his right eye he will see a vertical line due to the madoks rod.

4. The task is to read on which scale the vertical line lies (the value of its phoria without multifocal lenses) and report it to the inspector.

5. Both wheels turn to a multifocal lens, wherein one of the following three modes can be adapted: (1) degree increase: +1D, +1.5D, +2D, and the like; (2) degree reduction: +3D, +2.5D, and the like; (3) and (4) random sequence.

6. Repeat steps 3, 4 and 5 and write down values until all lenses (or a limited number of lenses, at the discretion of the inspector) have been tested.

Alternatively, step 2 can also be started with a different focal power. However, it is preferable to start the measurement with light added below zero.

Similarly, the apparatus of the second embodiment may further comprise an indicator (not shown) adapted to be adjusted by the subject to indicate the scotopic value obtained by the subject.

Moreover, the apparatus may further comprise a storage unit that records the phoria value of each test lens. Such recorded values may be sent to a database of a computer or cloud system that further analyzes the data for further processing, such as determining a personalized under-glow value for the subject.

When the device is used for fusion amplitude testing, the subject faces the dorsal side 1, i.e. the opposite side of the heterophoria measurement, and is viewed through two lisley prisms, and the fusion amplitude of the subject is measured by:

1. the distance d2 of the display device is adjusted to be the same distance as the phoria measurement. The device automatically changes the size of the straight letter on the display to this distance accordingly, so that the letters have the same angular size regardless of the distance.

2. The inspector sets the risley prism to zero.

3. The subject is asked to look at a target, typically a vertical word line, on the display.

4. The value of the prism is slowly and continuously increased until the subject reports a blur or ghost image.

5. The combined value of the lower risley prism is written as the fusion amplitude.

Similarly, the individualized under-glow value may be determined using, for example, the value obtained in the second embodiment.

According to a third embodiment of the invention (not shown), similar to the second embodiment, but in the second embodiment can be used only in one direction (heterophoria side), with a risley prism placed between the lens wheels and the eye opening on the front side, the fusion amplitude can be measured with different accommodation values. The phoria measurement may be converted to a fused amplitude measurement by rotating the wheels.

In this third embodiment, the phoria value is measured according to the phoria measuring step in the second embodiment. The risley prism is set to zero for all heterophoria measurements.

As for the blend amplitude measurement, similar to the second embodiment, the blend amplitude of all multifocal lenses can be determined in this embodiment, including a zero addition condition or a no lens condition.

Advantageously, in one variation, the apparatus further comprises a padded forehead headrest (not shown) positioned on the front side for positioning and receiving the forehead of the subject.

It should be noted that the above-mentioned embodiments serve as examples and are not to be construed as limiting the scope of the invention. On the basis of this, a person skilled in the art can expect other embodiments having the same function within the scope of protection of the present application.

Various other embodiments and variations and modifications to the disclosed embodiments will be apparent to those skilled in the art. In particular, all of the above-described features, alternatives and/or embodiments of the invention may be combined with each other, as long as they are not mutually incompatible or mutually exclusive, unless expressly mentioned. All such other embodiments, changes, and modifications are intended to fall within the scope of the appended claims.

Claims

1. An apparatus for measuring phoria of a subject, the apparatus comprising:

-a back side parallel to the front side, the back side comprising two further openings corresponding to the positions of the left and right eyes of the subject;

-a rear side parallel to the front side and positioned between the front side and the back side, the rear side having a visual display device arranged thereon, a side of the visual display device facing the front side presenting a visual display pattern of esophoria configured for use in esophoria measurements, wherein the visual display pattern of esophoria further comprises a light source for esophoria measurements, a side of the visual display device facing the back side presenting a visual display pattern of fused amplitude values configured for use in fused amplitude value measurements;

wherein the back side is slidable between the front side and the back side;

the front side of the apparatus further comprises an optical device positioned over an opening of the front side, the optical device comprising at least one set of lenses having different powers corresponding to different accommodation needs of the subject, wherein the apparatus comprises at least one specific lens positioned to correspond to the opening to assist the phoria measurement, wherein the optical device is positioned to correspond to the opening and in front of at least one eye of the subject such that the visual display pattern is adapted to be viewed by the subject through the optical device; the back side of the device further comprises a variable prism system for fusion amplitude testing, said variable prism system comprising two variable prisms positioned on two openings of the back side, respectively, the distance between said two variable prisms being adjustable.

2. The device according to claim 1, wherein the distance between the front side and the back side is adapted to be fixed at a close distance during said heterophoria measurement.

3. The apparatus according to claim 1, wherein the visual display pattern of phoria is adapted to be adjusted.

4. The apparatus according to claim 1, wherein the optical device comprises two sets of lenses positioned in front of the eyes of the subject, respectively, and both sets comprise the same lenses, wherein the order of the lenses on the two sets is configured to be reversed to mitigate binocular rotation.

5. The apparatus according to claim 4, wherein the distance between the optical centers of the lenses when using said two sets of lenses is adjustable to correspond to the pupil distance of the subject to align with the visual axis of the subject.

6. The apparatus according to claim 1, wherein the optical device comprises a null position in which no lens is positioned and no lens is seen by the subject.

7. The apparatus according to claim 1, wherein the number of lenses in the at least one set of lenses is limited to five lenses, the power values of the lenses being +1.00D, +1.50D, +2.00D, +2.50D, + 3.00D.

8. The apparatus of claim 7, wherein the power value of one lens of the at least one set of lenses is zero diopters.

9. The apparatus of claim 1, wherein the at least one particular lens is a Maddox filter or a vertical prism.

10. The apparatus according to claim 1, wherein the apparatus further comprises an indicator adapted to be adjusted by the subject to indicate a scotopic value obtained by the subject.

11. The apparatus of claim 9, wherein the indicator further comprises a memory unit that records a phoria value for each lens.

12. The apparatus according to claim 1, wherein the apparatus further comprises a padded forehead headrest positioned on the front side for receiving the forehead of the subject.