JPH11262474A - Sight examination instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sight examination instrument which automatically and easily determines sight abnormality in accordance with the movement of the eyeball. SOLUTION: An eyeball movement measuring device 2 is a lighting device using a fluorescent lamp or the like as a light source and having a built-line dimming means comprising a dimming inverter ballast. Measurements are made interlockingly with the dimming level of the lighting device, and the device comprises, e.g. a non-contact-type eve-camera with a trade name of IVEW, made by SMI CO. An SS measuring device 3 determines SS(saccadic span) at each illumination from the locus of the visual line recorded when a subject is made to read a specific sentence stimulus under conditions in which the level of illumination is varied in several steps. An SS comparison device 4 records SS data about healthy persons of every age in an internal memory to compare the data with the measurements made by the SS measuring device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual inspection apparatus used for diagnosis in ophthalmic medical treatment and the like.

[0002]

2. Description of the Related Art As one of inspection methods for judging eye diseases and visual abnormalities, there is a visual acuity test using a Landolt ring or the like. This quantitatively represents the resolving power of the eye when viewing the viewing target, and is generally performed because the inspection is easy.

[0003]

However, a disease or disease that is not caused by low visual acuity or abnormal visual acuity cannot be determined only by visual acuity measurement. For example, there have been reports of cases in which the character information of guidance displays and character information of traffic signs cannot be recognized, and the case of children who cannot understand sentences, even though their visual acuity is normal. Such a case is considered to be caused by some visual abnormality, but the cause cannot often be identified only from visual acuity measurement.

[0004] On the other hand, the above cases are considered to be caused by an abnormal cognitive manner. For example, in the case of a child who cannot understand a sentence, the sentence may not be recognized as character information in which characters are arranged, and may be viewed as a single figure.

[0005] In this case, the cause of the inability to understand the contents of the sentence often depends on the method of recognition, not on the visual acuity, and it is desired to easily find such abnormalities.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a visual inspection apparatus for easily determining a visual abnormality based on eye movement.

[0007]

Means for Achieving the Object The present invention measures eye movements when reading a sentence, and measures the size and variation of the distance between the gaze points from the gaze movement to the gaze point (SS: saccadic span). Is analyzed to detect visual abnormalities when reading characters.

[0008] The invention of a visual inspection apparatus according to claim 1 illuminates a illuminated unit on which sentence information is displayed and has a dimming unit capable of changing the illuminance of the illuminated unit to a plurality of levels; An eye movement measuring device that measures eye movement for each illuminance level when reading textual information; and from the trajectory of the gaze based on the trajectory of the subject's gaze corresponding to the measurement result of the eye movement measuring device at each illuminance level A sucker dick span measuring device for measuring the distance (SS: sucker dick span) between gazing points of the line of sight; and a means for comparing SS information of the subject with pre-registered reference information to determine an abnormality of the subject. It is characterized by having.

A visual inspection apparatus according to a second aspect of the present invention illuminates an illuminated unit on which sentence information is displayed, and has a dimming unit capable of changing the illuminance of the illuminated unit to a plurality of levels; An eye movement measuring device that measures eye movement for each illuminance level when reading textual information; and from the trajectory of the gaze based on the trajectory of the subject's gaze corresponding to the measurement result of the eye movement measuring device at each illuminance level A sucker span measuring device for measuring a distance (SS: sucker span) between gazing points of the line of sight; S for each illuminance level
S was regression-linearized by the least squares method in the illuminance range where there was a significant difference, and averaged in the illuminance range where no significant difference was observed. Means for determining abnormality.

Next, the operation will be described. The features of eye movements when reading a sentence will be described.

The movement of the line of sight when reading a document generally repeats "stop" and "jump". However, if the eye movements when reading a sentence are recorded, a "point of sight" in which the line of sight stays for a while at the time of stop occurs. A high-speed jumping movement (a saccadic movement, a moving distance is called a saccadic span) in which the line of sight moves at a high speed occurs between the gazing points.

The movement distance of this line of sight is defined as SS (saccadic sp
an), VD (viewing dura)
tion). Generally, SS and VD depend on the illuminance, and as the illuminance increases, the SS increases and the VD decreases, but after a certain illuminance, it tends to settle down to a certain value. And it is clear from the research of the inventors that the tendency of each change differs depending on the age. FIGS. 1 and 2 show the relationship between SS and VD and the illuminance.

[0013]

FIG. 1 shows an embodiment of the present invention.
It will be explained based on Fig. 4. FIG. 1 is a diagram showing a relationship between illuminance and SS (showing SS data of young and elderly people).

FIG. 2 is a diagram showing the relationship between illuminance and VD (showing SS data of young and elderly people).

FIG. 3 is a block diagram showing a first embodiment of the present invention in a block diagram.

FIG. 4 is a diagram showing a case where the subject is determined to be suspected of visual anomaly.

The black circles in FIG. 4 indicate abnormal values of SS.

In the first embodiment, reference numeral 1 denotes an illuminating device that incorporates dimming means including a dimming inverter ballast using, for example, a fluorescent lamp as a light source.

Reference numeral 2 denotes an eye movement measuring device for performing the measurement described in the operation in conjunction with the dimming level of the lighting device. For example, a non-contact type eye camera manufactured by SMI Corporation (trade name IVIEW)
Consists of

3 is an SS measurement in which the SS (saccadic span) is determined for each illuminance from the locus of the recorded line of sight when the subject reads a specific sentence stimulus in a situation where the illuminance level is changed in several stages. Device.

Reference numeral 4 denotes an SS comparison device, in which SS data of healthy persons by age is registered in an internal memory, and performs comparison judgment with a measurement value of the SS measurement device.

First, in a situation where the illuminance level is changed in several stages, the subject is caused to read a specific sentence stimulus. Using an eye movement measuring device, record the eye movement (the trajectory of the line of sight) at this time. From the recorded trajectory of the line of sight, SS (saccadic span) is determined for each illuminance.

When a healthy person reads a sentence, as shown in FIG. 1, the SS rises with the illuminance, and becomes constant when the illuminance exceeds a certain illuminance. Although this tendency slightly differs depending on the age, the SS does not change from a certain illuminance or higher.

However, the SS data of the subject is
If it does not apply to the change tendency of S (for example, if the standard deviation is found, the SS variation at specific illuminance is large, SS is large even at low illuminance, etc.), eye movement different from normal reading of text has occurred It can be judged that there is a suspicion of visual abnormality. In the present embodiment, for example,
It is effective for use in ophthalmological medical institutions. The second embodiment is the same as the first embodiment up to the point where the SS is obtained. However, in the illuminance range where there is a significant difference in the SS for each illuminance level, the least square method is used. In the illuminance range where no
It is also possible to determine the subject's abnormality when there are multiple or no intersections of each regression line.

When the SS of the subject comes out, a comparison is made with the change tendency of the SS of a healthy person registered by age registered in advance, and the age of the subject is similar to the data. In this way, it is possible to determine how old a subject's ability to read letters corresponds to a healthy person. This invention is effective for visual inspection of, for example, a driving school.

[0026]

According to the invention of the visual inspection apparatus of the first aspect, the measurement result of the eye movement measuring apparatus at each illuminance level by the illuminating apparatus having the dimming means which can be changed to a plurality of levels and the saccharic span measuring apparatus. The distance between the gazing points of the line of sight is measured from the trajectory of the line of sight based on the trajectory of the line of sight of the subject, and by comparison with the information of a healthy person,
An abnormality can be easily determined.

According to the invention of the visual inspection device of claim 2,
A lighting device having dimming means that can be changed to a plurality of levels and a saccharic span measuring device allow the gaze to be determined from the trajectory of the subject based on the trajectory of the subject's gaze according to the measurement result of the eye movement measuring device at each illuminance level The distance between fixation points was measured, and the SS for each illuminance level was regression-linearized by the least squares method in the illuminance range where there was a significant difference, and averaged in the illuminance range where no significant difference was observed. Since there is a means for determining the subject's abnormality when there are a plurality of intersections or no such intersections, highly accurate abnormality determination can be performed while automating troublesome calculations and the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between illuminance and SS (showing SS data of young and elderly people).

FIG. 2 is a diagram showing the relationship between illuminance and VD (showing SS data of young and elderly people).

FIG. 3 is a block diagram showing a first embodiment of the present invention in a block diagram.

FIG. 4 is a diagram illustrating a case where a subject is determined to be suspected of visual anomaly.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1: Illumination device 2: Eye movement measurement device 3: SS measurement device 4: SS comparison device

Claims (2)

[Claims] An illumination device for illuminating the illuminated means on which the text information is displayed, and having a dimming means capable of changing the illuminance of the illuminated means to a plurality of levels; an eyeball when a subject reads the text information An eye movement measuring device for measuring the movement for each illuminance level; a distance (SS) from the trajectory of the gaze to the gaze trajectory based on the trajectory of the gaze of the subject according to the measurement result of the eye movement measuring device at each illuminance level : Saccadic span measuring device for measuring the (saccadic span); and means for comparing the SS information of the subject with pre-registered reference information to determine the abnormality of the subject. Visual inspection device. 2. An illumination device for illuminating an illuminated means on which text information is displayed, and having a dimming means capable of changing the illuminance of the illuminated means to a plurality of levels; an eyeball when a subject reads the text information An eye movement measuring device for measuring the movement for each illuminance level; a distance (SS) from the trajectory of the gaze to the gaze trajectory based on the trajectory of the gaze of the subject according to the measurement result of the eye movement measuring device at each illuminance level : Saccadic span measurement device for measuring the sacchard span); SS for each illuminance level is regression-linearized by the least squares method in the illuminance range where there is a significant difference, and averaged in the illuminance range where no significant difference is observed. Means for judging a subject's abnormality when a plurality of intersections of each regression line exist or do not exist.