JP2000126130A - Night visual acuity examining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily maintain an opened eye at the time of a light adaptation without making a subject get bored, and stably and easily perform the confirmation of the eye opened state as well by providing a target presenting means which is a means to present a target catching attention of a subject eye at the time of a light adaptation by a dark adaptation examining means, and makes the presenting state of the target variable. SOLUTION: For an index disk palate 121 which constitutes an index presenting section 20, a Landolt's ring indexes in four directions of right, left, up and down in respective 12 stages of visual acuity values, and a shielding plate which shields an index window 11a at the time of a light adaptation are concentrically provided, and by the rotation of a motor 22, an aiming examination index or the shielding plate is selectively arranged in the index window 11a. Behind the index disk plate 21, a half mirror 23 is provided, and in the transmitting direction, an illuminating lamp 24 which is lit in a normal visual acuity examination is arranged, and also, in the reflecting direction, a diffusion plate 25, and an illuminating lamp which is lit in a dark adaptation, are arranged. At the time of a normal visual acuity measurement, an examination index is presented by the illuminating lamp 24, and in a dark adaptation measurement, a dusk brightness is provided by the illuminating lamp 26 and the diffusion plate 25, and an examination index is presented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a night vision test apparatus used for driving aptitude test and the like.

[0002]

2. Description of the Related Art For example, when driving a car, assuming that the vehicle suddenly enters a dark tunnel during the day, the user can see a space corresponding to the brightness during the day for a certain period of time (for example, 30 seconds). 2. Description of the Related Art There is known a night vision test apparatus in which a visual target is presented in a dark visual field after an optometry is subjected to light adaptation, and a dark adaptation test is performed to measure a time until the visual target can be visually recognized. Some devices of this type are provided with an eyelid detection mechanism for detecting that the eyelid is closed in order to prevent the subject from pinching their eyes during light adaptation. When the presence is detected, the examiner is notified by a lamp display.

[0003]

However, the above-mentioned conventional apparatus has the following problems.

During light adaptation, the subject's eye only shows a simple bright space without irritation, and the subject (especially an elderly subject) holds his / her eye for 30 seconds during light adaptation. Keeping it open is painful and boring.

Further, the eyelid detection mechanism detects reflected light from the eyelid of the subject with a sensor. However, since the reflectance of the eyelid varies depending on the subject, the detection result tends to be unstable. Further, adjustment of the detection sensitivity of the sensor is required for each subject, which is troublesome. The present invention has been made in view of the above-described problems of the conventional apparatus, and has an object to provide an apparatus that can easily maintain an open eye during light adaptation without getting tired of the eye and that can easily and stably check an eye open state. And

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) Dark adaptation inspection means for presenting an optotype in a dark visual field and then examining the appearance of the subject after photoadaptation to the eye to be inspected, and applying an optotype to the eye during light adaptation by the dark adaptation inspection means. A target presenting means for presenting a target to be noticed, characterized by comprising target presenting means for changing a presentation state of the target.

(2) In the night vision test apparatus of (1), the subject is made to respond to the presentation state of the target presented by the target presentation means.

(3) In the night vision test apparatus of (1), an input means for inputting a response of the presentation state of the target, and whether the response by the input means is correct or incorrect with respect to the presentation state of the target is determined. An eye opening determining means for determining an open state of the subject's eye based on the determination result.

(4) The night vision test apparatus according to (3), further comprising a notifying means for notifying the result of the judgment by the eye-opening judging means.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the appearance of the device of the present embodiment. Reference numeral 1 denotes an apparatus main body. An inspection window 2 is provided on an upper part of the apparatus main body 1 so that a subject can look into a target presented inside the main body. An operation panel 3 for a user and a printer 8 are arranged. A joystick 5 for the subject to respond to the presented target in the direction of the presented target, a response button 4 for responding that the target can be read,
A start switch 6 for starting an inspection in an automatic inspection mode described later is provided. Reference numeral 9 denotes a speaker to which a voice guide instruction is output.

FIG. 2 is a diagram showing the configuration of an optical system and a control system inside the apparatus. A lens 10 is disposed in the inspection window 2, and an inspection target presented by the target presenting unit 20 behind the lens 10 has an apparent inspection distance of 5 m from the subject's eye. Between the lens 10 and the optotype presenting section 20, a visual field space for making the eye to be examined light-adapted is secured by the internal cover 11, and the optotype of the optotype presenting section 20 is an optotype window 11.
a. Matte white paint is applied to the inner surface of the inner cover 11, and the illumination lamp 12 is used for light adaptation.
The luminance of about 5700 cd / m ² is obtained by lighting of. The illumination lamp 12 is placed at a position where the illumination light does not directly enter the subject's eye.

An optotype disc plate 21 constituting the optotype presenting section 20 has a visual acuity value of 0.1 to 1.0, 1.2, 1.5.
Landolt ring targets in four directions, left, right, up and down, respectively, and a shielding plate (coated with matte white paint similar to the inner cover 11) for shielding the target window 11a during light adaptation are provided on concentric circles in two stages. The test optotype or shielding plate expected by the rotation of the motor 22 is selectively arranged in the optotype window 11a. A half mirror 23 is provided behind the optotype disc plate 21, and an illumination lamp 24 that is turned on during a normal visual acuity test (still visual acuity test) is disposed in the transmission direction of the half mirror 23. On the direction side, a diffusion plate 25 and an illumination lamp 26 that is turned on during dark adaptation measurement are arranged. At the time of normal visual acuity measurement, the test target is presented by the illumination lamp 24 at a luminance of about 160 cd / m ^{2, and} at the time of dark adaptation time measurement, the illumination lamp 26 and the diffusing plate 25 dim the darkness of about 0.1 to 0.15 cd / m ^2. The test target is presented with the brightness.

As shown in FIG. 3 (the figure is a view when the optotype window 11a is viewed from the eye to be inspected), red light is emitted on the inner cover 11 near the optotype window 11a. Four LEDs 13 are arranged in the up, down, left, and right directions.
The ED 13 is selectively turned on at the time of light adaptation, and functions as a target object that stimulates the eye to be examined and attracts attention. Further, a lamp 14 (having a brightness equivalent to a vehicle headlamp) which is turned on at the time of measuring the visual acuity under glare is disposed slightly away from the left and right sides of the target window 11a. In the glare-based visual acuity measurement, the lamp 14 is turned on to examine the influence of visual acuity when the vehicle is dazzled by a headlight of an oncoming vehicle during driving of the vehicle at night.

In FIG. 2, reference numeral 30 denotes a control unit for controlling the entire apparatus, and includes a lamp, a motor 22, a voice guide generator 31 connected to the speaker 9, a response button 4, a joystick 5, an operation panel 3, and the like. , A memory 33 storing an inspection program is connected.

The operation of the above apparatus will be described with reference to the switch configuration diagram of the operation panel 3 shown in FIG. In this apparatus, the examiner operates each switch of the operation panel 3 to obtain a verbal response of the subject to proceed with the examination, and the examinee performs the switch operation by the voice guide. The examinee does not operate the joystick 5 with respect to the automatic mode in which the examination proceeds according to a predetermined program and the response of the optotype contents to the automatic mode, and the examiner does not operate the joystick 5 as the verbal answer of the examinee There are prepared three inspection modes, a semi-automatic mode, in which an inspection is advanced by operating a switch on the operation panel 3, and any one of the inspection modes is selected by the mode selection switch 40. Less than,
It will be described in order.

<Automatic Mode> In this mode, the normal eyesight measurement (still eyesight measurement), the dark adaptation time measurement, and the visual acuity measurement under glare are sequentially programmed.

When the subject presses the start switch 6, normal visual acuity measurement is first started. The control unit 30 controls the driving of the optotype presenting unit 20 and the lighting of the illumination lamp 24 to present an optotype with a visual acuity value of 0.5 to the optotype window 11a. When the direction of the target is determined by the voice guide, the subject is instructed to tilt the joystick 5 in that direction. When the subject responds to the joystick 5 with the determination result of the optotype, the control unit 30 determines the correctness. If the response is correct, an optotype with an increased visual acuity value is presented, and if incorrect, an optotype with a reduced visual acuity value is presented. If the answer is raised by one step or the judgment cannot be made (if the answer is unreadable, the response button 4 is pressed), the visual acuity value is returned to the visible level, and the test is continued by changing the direction of the target. As a result of the determination of correctness by the control unit 30, if there is a correct answer twice or more with the same visual acuity target, the visual acuity value is determined as having the visual acuity.

Subsequently, a program for measuring the dark adaptation time is executed. The voice guide announces that the lamp is turned on and becomes bright for 30 seconds, and the LEDs around the center are turned on. Therefore, the subject is instructed to tilt the joystick 5 in that direction. After instructing the voice guide, the control unit 30
, The motor 22 is driven, and the shielding plate provided on the optotype disc plate 21 is placed in the optotype window 11a, and the illumination lamp 12 is turned on to illuminate the visual field space seen by the subject's eye. Further, any one of the four LEDs 13 is turned on. The subject is led 1 with the joystick 5
In response to the lighting direction of No. 3, the control unit 30 automatically determines whether the subject has opened his or her eyes from the result of the correctness (that is, if the answer is correct, the eyes are opened). If the answer is wrong, the eyes may not have been able to open their eyes.) If the response from the joystick 5 is incorrect, an instruction to open the eyes is provided by a voice guide.

The selective lighting of the LED 13 and the response by the subject are repeated for 30 seconds. During this light adaptation, the subject pays attention to the lighting of the LED 13 and adds an operation to respond to it, so that it is less tedious to open the eyes than in the case of simply looking in a bright space. .

The presenting of the target to the subject's eye during the light adaptation is performed by turning on and off the LED 13 so that the four lights appear to rotate and move, and then the lighting direction of the LED 13 finally turned on. Is effective because there is a change in the presentation of the optotype and a stimulus can be further given to the subject.

When approaching the end of the light adaptation time, a voice guide announces "After darkening, immediately turn the lever in the direction in which the ring is cut off when the target is visible." After the end of the light adaptation time, the illumination lamp 12 is turned off and a target having a visual acuity value of 0.2 is placed in the index window 11a, and the target is presented by the illumination lamp 26 and the diffuser plate 25 with dim brightness. . The control unit 30 measures the time from the start of the optotype presentation. If the subject responds to the interpretation of the optotype with the joystick 5 and the result is determined to be valid, a response signal of the joystick 5 is input. Is stored as a measurement result.

Next, a measurement of visual acuity under glare is performed. After the subject is instructed by the voice guide to gaze at the target and respond in the direction of the presented target, the lamps 14 on both sides of the target window 11a are turned on. In the optotype window 11a, an optotype having a visual acuity value of 0.5 (or an optotype having a visual acuity value finally determined by the normal visual acuity measurement) is presented. 30. Based on the result, the next presentation target is determined. If there is a correct answer twice or more with the same visual target, the visual acuity value is determined as having the visual acuity.

When the examination is completed, the printer 8 automatically prints out each measurement result, the judgment result of each measurement, and the contents of the general instruction.

<Manual Mode> The examiner selects the manual mode by the switch 40 and selects the eye to be measured by the switch section 41. Further, the measurement items of the normal visual acuity measurement, the dark adaptation time measurement, and the visual acuity measurement under glare are selected by the switches 42, 43, and 44.

Normally, visual acuity measurement is performed as follows. The visual acuity value of the visual target presented by the visual acuity switch 45a is selected.
Four optotype switches 4 provided at the center of the operation panel 3
The direction of the target presented in 6a to 46d is selected. The optotype selected under the control of the control unit 30 is presented in the optotype window 11a. The selected visual acuity value is displayed on the display 45b,
Each of the optotype switches 46 according to the direction of the optotype selected.
Lamps 37a to 37d arranged near a to 46d are turned on. The examiner asks the subject about the discrimination of the target,
The lamps 37a to 37d determine whether the verbal response of the subject is correct or not.
Confirmation is made by the lighting of, and the inspection proceeds. The visual acuity value displayed last is used as the measurement result.

The dark adaptation time is measured as follows. When the dark adaptation time measurement switch 43 is pressed, the illumination lamp 12 is turned on to illuminate the visual field space seen by the subject's eye. At the same time, the measurement of the light adaptation time is started by the control unit 30, and the time is displayed on the display 49. At the time of this light adaptation, the LED 13 is turned on in the same manner as in the automatic mode, and the direction of the LED 13 is asked by the subject. The direction of the LED 13 to be turned on is selected by the examiner using the optotype switches 46a to 46d. The examiner is L
The lighting direction of the ED 13 is asked to the subject, and the lighting direction is sequentially changed while checking the answer. Here, if the subject's response is wrong, the user is warned to open his eyes. If a correct answer is obtained, it is confirmed that the subject has opened his eyes during light adaptation.

When the light adaptation time is over, the illumination lamp 12
Is turned off and a target having a dim visual acuity value of 0.2 is presented in the index window 11a. Further, the time from the start of the presentation of the optotype is counted by the control unit 30, and the time is displayed on the display 49. When the subject can read the direction of the optotype, he / she presses the response button 4 and answers the direction. When the signal from the response button 4 is input, the time display on the display 49 stops, and when the direction to which the subject has answered is correct, the time from the start of the presentation of the optotype becomes a measured value. If there is an error, the switch 50 is pressed to perform re-measurement.

The switch 44 is used to measure the visual acuity under glare.
push. When this switch is pressed, the lamps 14 on both sides of the optotype window 11a are turned on. In this state, the examiner selects the visual acuity value and the direction of the presented visual target with each switch and measures the visual acuity value under glare in the same manner as in the normal visual acuity test. When the print switch 55 is pressed, each measurement result obtained as described above and the comprehensive instruction content are printed out.

<Semi-automatic mode> When the subject presses the start switch 6, each measurement proceeds according to a voice guide instruction in accordance with a program having the same procedure as in the automatic mode, but is presented in the optotype window 11a. With respect to the determination of the target and the determination of the lighting direction of the LED 13 at the time of light adaptation, the subject does not respond with the joystick 5 but the examiner obtains the verbal answer of the subject and the target switch 46a to 46b. Input at 46d. The correctness is determined by the control unit 30. The response to the determination of the Landolt's ring target in the dark adaptation time measurement is input by pressing the response button 4.

Such a semi-automatic mode is conveniently used when the subject is not good at operating the joystick, and the examiner is unfamiliar with the examination or saves the labor of the examiner.

In the embodiment described above, the LED 13 arranged around the optotype window 11a is used as a target to be presented to the subject's eye during light adaptation.
It is also possible to present a Landolt ring target arranged at 1a and to respond to the direction.

[0033]

As described above, according to the present invention,
By presenting the optotype at the time of light adaptation and letting the subject respond to the contents, the eye opening at the time of light adaptation can be easily maintained without getting bored, and the confirmation of the eye open state is stable and easy. I can do it.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an appearance of a device according to an embodiment.

FIG. 2 is a diagram showing a configuration of an optical system and a control system inside the apparatus.

FIG. 3 shows the arrangement of LEDs selectively turned on during light adaptation.
FIG. 4 is a diagram illustrating an arrangement of lamps that are turned on when measuring visual acuity under glare.

FIG. 4 is a diagram showing a switch configuration of an operation panel.

[Description of Signs] 1 Apparatus main body 3 Operation panel 5 Joystick 11 Inner cover 11a Optotype window 12 Illumination lamp 13 LED 20 Optotype presenting section 30 Control section 33 Memory

Claims (4)

[Claims] 1. A dark adaptation inspection means for presenting a visual target in a dark visual field and examining the appearance thereof after the eye to be inspected is photoadapted, and paying attention to the eye to be examined at the time of light adaptation by the dark adaptation inspection means. A night vision test apparatus comprising: target presenting means for presenting a target to be made, and target presenting means for changing a presenting state of the target. 2. The night vision test apparatus according to claim 1,
A night vision test apparatus wherein a subject is made to respond to a presentation state of a target object presented by the target object presenting means. 3. The night vision test apparatus according to claim 1,
Input means for inputting a response to the presentation state of the target, and eye opening determination for determining whether the response from the input means is correct to the presentation state of the target and determining the eye open state of the subject's eye based on the determination result Means at night. 4. The night vision test apparatus according to claim 3,
The night vision test apparatus further comprises a notifying unit for notifying a result of the determination by the eye opening determining unit.