JPH09271461A - Ophthalmometer - Google Patents

Abstract

(57) [Abstract] [Purpose] With a simple configuration, an examinee himself / herself performs a simple operation to measure an accurate refraction value and corrected visual acuity. [Configuration] A corneal reflection image S is a reflection surface P of a prism 10.
Two-beam images T1 and T2 are received on the linear array sensor 23 via the lens 20 and the cylindrical lens 22. First, the stepping motor 19 is rotated to present the striped target N having a visual acuity of 0.1, and the subject makes a response by tilting the response lever 6 of the response means 5 through the objective lens 4. When the stripe direction is unknown, until the response to the mark M0 direction or the response to the wrong stripe direction, the stripe direction is randomly selected and gradually fine stripe targets are presented. The most distant diopter at the maximum visual acuity is obtained in the three meridian directions, the subjective refraction value including astigmatism is calculated from this, and the striped visual acuity in the three meridian directions at that time is averaged to obtain the corrected visual acuity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometry device used for subjective optometry in an ophthalmology hospital, an eyeglass store, or the like.

[0002]

2. Description of the Related Art Conventionally, a subjective eye examination apparatus uses a radial chart or a multi-point chart and illuminates it with a single illumination light source as a Landolt ring or a character as a visual target and presents it to a subject.
The examiner always measures the visual acuity by adjusting the distance of the eye to be inspected to a predetermined position.

[0003]

However, in the above-described conventional optometry apparatus, the process for presenting the optotype becomes long, and in particular, in the case of accurately measuring the eye to be examined with astigmatism, a large number of optotypes are used. It takes longer to measure because it is necessary to use, and since the central light source and peripheral area of the visual target field are illuminated by the same light source, it is not possible to change the illumination condition individually, so the subject can clearly There is a problem that the target cannot be recognized. Furthermore, since the anterior segment of the subject blocks the light, the predetermined position of the subject's eye is detected and aligned, so the distance of the subject's eye cannot be kept constant, and the position There is a problem that the alignment mechanism becomes complicated.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide an optometry apparatus capable of measuring an accurate refraction value and corrected visual acuity by a simple operation by the subject himself / herself with a simple configuration.

[0005]

The eye examination apparatus according to the first aspect of the present invention for achieving the above object, is an optotype presenting means for sequentially presenting at least three directions of striped optotypes with variable diopter, and a subject. It has a response input means for inputting the response of 1 and a calculation means for calculating a refraction value or visual acuity based on the response of the subject to the presented visual target.

The optometry apparatus according to the second invention is at least 3
It is characterized in that it has a striped visual acuity measuring means for measuring a striped visual acuity in a direction and a computing means for computing a visual acuity from the striped visual acuity.

An optometry apparatus according to a third aspect of the present invention has a diopter variable target optical system and target means for illuminating the target and its peripheral visual field with different light sources, and turns on the light source at different timings. It is characterized by

An optometry apparatus according to a fourth aspect of the invention has a refracting power measuring means for measuring a refraction value of an eye to be inspected and a distance measuring means for measuring a distance to the eye to be inspected, and the refraction value is corrected by the measured distance. It is characterized by doing.

An optometry apparatus according to a fifth aspect of the present invention comprises an optotype means for presenting an optotype illuminated by a light source to an eye to be inspected, and a detection means for detecting whether or not a part of a subject's face is hit. And a face contact means for controlling lighting of the light source according to a signal from the detection means.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows a front view of an optometric apparatus for measuring the subjective refraction value, the naked eye visual acuity, and the corrected visual acuity according to the first embodiment. On the front surface of the main body 1 of the apparatus viewed from the side of the subject, a left eye forehead support 2 and a right eye forehead support 3, an objective lens 4, a response lever 6 of the response input means 5, and a printer 7 are arranged from the upper side. Therefore, a micro switch (not shown) for detecting that the subject's forehead is in contact is attached to each of the left and right eye brow pads 2, 3.

FIG. 2 is a plan view of the response input means 5. Marks M1, M2, M3 representing three-direction striped targets around the response lever 6 and marks for responding that no stripe is visible. M0
Is drawn.

FIG. 3 is a block diagram of the optical system showing the apparatus main body 1
On the optical path O1 passing through the center of the objective lens 4 provided at a position facing the eye E to be inspected, a prism 10 having a reflecting surface P that partially reflects near infrared light and transmits visible light, and a stepping motor. Target unit 1 having driving means 11 such as
2 is arranged, and the optotype unit 12 is driven by the drive means 11 in the optical path O1 direction so that the diopter of the eye E can be changed. The response output of tilting the response lever 6 of the response input means 5 is connected to the arithmetic control means 13, and the output of the arithmetic control means 13 is connected to the drive means 11 of the optotype unit 12.

The optical path O1 in the target unit 12 is shown in FIG.
As shown in Fig. 5, the opening 14a is formed in the center and the distant view D
The peripheral optotype plate 14 on which is drawn, and various striped optotypes N are arranged on the circumference as shown in FIG. 5, and the selected striped optotype N is located at the rear of the opening 14a of the peripheral optotype plate 14. The target disc 15, the diffusion plate 16, and the striped target N presented from behind
Illumination light sources 17 for illuminating the are sequentially arranged. An illumination light source 18 that illuminates the peripheral optotype plate 14 from the front is arranged around the optical path O1, and a rotation shaft of a stepping motor 19 is connected to the center of the optotype disc 15. The striped target N is a set of three directions N1, N2, and N3 at intervals of 60 degrees, and the one-striped interval corresponds to a striped visual acuity of 1.0, so that the visual acuity is 1.5 to 0. It is composed of various stripe pitches up to 1.

When viewed from the eye E side of the optical system for distance measurement arranged in the reflection direction of the prism 10, it becomes as shown in FIG. 6. In FIG. 6, for convenience of explanation, the optical paths O1 and O2 are on the same straight line. It is drawn in. That is, the lens 20, the light blocking member 21, the cylindrical lens 22, and the linear array sensor 23 are sequentially arranged in the reflecting direction of the reflecting surface P of the prism 10 adjacent to the objective lens 4.

With the above structure, the subject puts his face on his forehead 2
Alternatively, the light sources 17 and 18 for illumination are turned on when the light sources 3 and 3 are applied. The device body 1 recognizes whether the eye E to be measured is the left eye or the right eye, depending on which of the forehead supports 2 and 3 is turned on. The peripheral visual target plate 14 is illuminated from the front by the illumination light source 18, and the striped visual target N in the optical path O1 direction is illuminated from the rear by the illumination light source 17 via the diffusion plate 16. The target luminous flux reaches the eye E through the prism 10 and the objective lens 4, and the subject recognizes the distant view D of the peripheral target plate 14 and the striped target N seen from the opening 14a, and the cornea C shows the cornea. The reflected image S is formed.

The corneal reflection image S returns to the optical path O1 and the prism 1
The light beam is reflected by the reflection surface P of 0, is condensed by the lens 20 to the rear of the linear array sensor 23, the central light beam is blocked by the light blocking member 21, and the two-beam image T1 is projected on the linear array sensor 23 by the cylindrical lens 22. Collected as T2.
It is also possible to dispose a lens separately to collect the light flux on the linear array sensor 23, and then use a prism to separate the two light flux images T1 and T2 on the linear array sensor 23.

When the corneal reflection is detected by the linear array sensor 23, the measurement is started assuming that the eye E is in a predetermined position. Initially, the diopter is 0 diopter. First, the stepping motor 19 is rotated to select and present the striped target N having a visual acuity of 0.1. The subject looks at the striped target presented through the objective lens 4 and tilts the response lever 6 in any one of the three-direction marks M1, M2, M3 according to the direction to make a response, which is correct. If the response is in the direction, a finer striped target N is presented.

At this time, if the illumination light source 17 is once turned off, and a new striped target N is presented at the same time, the illumination light source 17 is turned on again at the same time. Can be recognized. Note that a sound may be emitted, and in this case, the fact that the apparatus body 1 recognizes the response made by tilting the response lever 6 is notified by issuing another sound.

When the stripe direction is unknown, the response lever 6 is tilted toward the mark M0 to respond. And mark M0
Until there is a response to the direction
The stripe directions are randomly selected and gradually fine stripe targets are presented. At this time, the diopter of the inspected eye E is roughly estimated from the visual acuity at the time of wrong direction response or unknown response, that is, the pitch of the striped target N to determine the diopter of the striped target N to be presented next. Good to do.

Normally, it is assumed that the corrected visual acuity is about 1.2, but the larger the refractive error, the worse the visual acuity at 0 diopter. , This relationship should be decided in advance. The target is moved to the estimated diopter and 0.
Presentation is started from a target with an intermediate visual acuity of about 5, and the visual acuity is obtained by finely adjusting the target pitch until an unknown response.

In this way, the farthest diopter at the maximum visual acuity is obtained in the three meridian directions, and the index diopter and pitch presented at that time are estimated diopter and estimated visual acuity from the responses so far. By estimating, the number of presentations is determined to be small. The change of the diopter in the meridian direction is made sinusoidal, and the subjective refraction value including astigmatism is calculated from the diopters of the three meridians,
The striped visual acuity in the three meridian directions at that time is averaged to obtain corrected visual acuity. Note that the naked eye's visual acuity is 3 with the target fixed at 0 diopter.
The stripe visual acuity of the meridian is measured and averaged.

During the measurement, the calculation control means 13 calculates the distance to the eye E from the distance between the two light flux images T1 and T2 on the linear array sensor 23 due to corneal reflection, and the measured subjective refraction from this value is calculated. The measured value is constantly corrected. In this way, even if there are individual differences in the distance from the subject's forehead to the eyes, there is no need to perform distance adjustment for each subject,
Even if the distance of the eye E to be inspected does not match accurately at the time of measurement, it is possible to always perform an automatic correction to obtain an accurate refraction value, so that the subject can perform the measurement independently without the examiner. it can.

Further, when the forehead separates from the forehead rest 2 or 3 during measurement, the microswitch detects this and the illumination light source 17 is turned off or blinks to warn the subject. Furthermore, the illumination light source 18 also disappears when the state of being separated for a predetermined time or more continues. In this case as well, a sound warning may be given.
When the measurement is completed in this way, the result is printed on the printer 7, and the illumination light sources 17 and 18 are turned off.

FIG. 7 is a block diagram of the second embodiment, in which the response input means 5, the driving means 12, the arithmetic control means 13 and the like are the first.
The illustration is omitted because it is the same as the embodiment of FIG. 1 forehead
A single dichroic mirror 30L that opposes the left and right eyes EL and ER on the respective optical paths O3L and O3R and serves as a half mirror for infrared light and transmits part of the corneal reflected light by the target light. 30R, mirrors 31L and 31R are arranged, and the mirror 32 is arranged in the reflection direction of the mirror 31.
A half mirror 33, a lens 34, a separating prism 35 for vertically separating the light flux, and an area CCD 36 are sequentially arranged in the reflecting directions of the mirrors 31R and 32.
Then, on the optical paths O4L and O4R in the respective reflection directions of the dichroic mirrors 30L and 30R, a lens 37L,
37R and optotype units 38L and 38R are arranged.

The dichroic mirrors 30L, 30
As described above, R is a half mirror for infrared light, reflects the target light from the target units 38L and 38R, and a part of the corneal reflected light from the eye E to be inspected by the target light. Through. In addition, dichroic mirrors 30L, 3
0R is driven in the optical path O4 direction in conjunction with each other to correct the interpupillary distance.

The target light passes through the mirrors 31L, 31R, 32, the half mirror 33, the lens 34, and the separation prism 35, and is received by the area CCD 36. Cornea reflection images A1, A2, B1, B2 as shown in FIG. It is imaged. Corneal reflection image A1,
A2 is from the left eye, corneal reflection images B1 and B2 are from the right eye,
These positions are calculated by the calculation control unit 13, the distance between the dichroic mirrors 30L and 30R is controlled from the distance between the left and right images, and the refraction value is calculated based on the distance obtained from the distance between the upper and lower images.

FIG. 9 is a block diagram of the third embodiment, showing the optical path.
A cross cylinder 41 having a driving means 40, an objective lens 42, and a target unit 44 having a driving means 43 are sequentially arranged on O1, and the cross cylinder 41 is composed of a combination of two cylindrical lenses. Astigmatism is corrected by changing the angle. The output of the control calculation means 45 is connected to the drive means 40 and 43, and the other structure is similar to that of FIG.

In a subject with strong astigmatism, the striped target N appears to be blurred, so the measurement is performed twice. That is, at first, the approximate 3 meridional refraction value is measured without correcting astigmatism by the procedure described in the first embodiment, the cross cylinder 41 is set so as to correct the measured astigmatism, and the same operation is performed again. The driving means 43 is moved in a procedure to measure the 3 meridional refraction value. A refraction value including astigmatism is calculated from the three meridional refraction values and the set value of the cross cylinder 41. It should be noted that any meridian may be measured as long as it is three or more meridians, and in this way, an accurate refraction value can be measured even in the eye E with strong astigmatism.

[0029]

As described above, the optometry apparatus according to the first aspect of the present invention presents a three-direction striped target with variable diopter, and calculates the refraction value or visual acuity according to the response of the subject. ,
The subjective refraction value including astigmatism can be easily measured with a simple operation.

Since the eye examination apparatus according to the second aspect of the invention calculates the visual acuity from the three directions of the visual acuity, accurate visual acuity can be measured in a short time even with an astigmatic eye.

In the optometry apparatus according to the third aspect of the invention, the optotype and the peripheral optotype are illuminated by different light sources at different timings, so that the subject can clearly recognize the optotype and the optometry can be performed in a short time. It can be performed.

In the eye examination apparatus according to the fourth aspect of the present invention, the refraction value is corrected by the distance to the subject measured by the distance measuring means. Therefore, the examiner does not need to adjust the distance to the subject's eye. It will be easy.

In the eye examination apparatus according to the fifth aspect of the present invention, the face contacting means detects that a part of the face is hit and controls the lighting of the light source for illumination, so that the distance to the eye to be examined is constant. It is possible to maintain accurate optometry.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment.

FIG. 2 is a configuration diagram.

FIG. 3 is a plan view of a response input unit.

FIG. 4 is an explanatory diagram of a visual target field.

FIG. 5 is a configuration diagram of a distance measuring optical system.

FIG. 6 is a plan view of the optotype plate.

FIG. 7 is a configuration diagram of a second embodiment.

FIG. 8 is an explanatory diagram of a corneal reflection image on a CCD.

FIG. 9 is a configuration diagram of a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2, 3 Forehead support 5 Response input means 7 Printer 10 Prism 12, 38L, 38R, 44 Target unit 13, 45 Control calculation means 14 Peripheral target board 15 Target disk 17, 18 Illumination light source 21 Light-shielding plate 23 Linear array sensor 30L, 30R Dichroic mirror 35 Separation prism 36 Area CCD 41 Cross cylinder lens

Claims (5)

[Claims] 1. An optotype presenting means for sequentially presenting at least three directions of striped optotypes with variable diopter, a response inputting means for inputting a response of the examinee, and a response of the examinee to the presented optotype. An optometry apparatus comprising: a calculation unit that calculates a refraction value or visual acuity. 2. An optometry apparatus comprising: a fringe visual acuity measuring means for measuring fringe visual acuity in at least three directions; and a computing means for computing visual acuity from the fringe visual acuity. 3. A diopter-variable optotype optical system, and an optotype means for illuminating the optotype and its peripheral visual field by different light sources,
An optometry apparatus, wherein the light source is turned on at different timings. 4. An optometry apparatus comprising: a refracting power measuring means for measuring a refraction value of an eye to be inspected; and a distance measuring means for measuring a distance to the eye to be inspected, wherein the refraction value is corrected by the measured distance. apparatus. 5. An optotype means for presenting an optotype illuminated by a light source to an eye to be inspected, and a face-applying means provided with a detection means for detecting whether or not a part of the face of the subject is hit. Then, the optometry apparatus for controlling the lighting of the light source according to the signal of the detection means.