Perimeter

Abstract

A diopsimeter comprises a display (1), an infrared light-emitting diode (2), a CCD camera (3), a half-silvered mirror (4), an image processing device (5), a computer (6), and an operation switch (7). The computer (6) displays a fixing target for fixing the line of sight of a subject and light stimulus targets for giving light stimulus to the pupil of the subject at predetermined positions of the display (1). The infrared light-emitting diodes (2) projects infrared radiation toward the eye ball of the subject. The CCD camera (3) images the eye ball of the subject by using the projected infrared radiation. The image processing device (5) detects the diameter of the pupil of the subject from captured image. The computer (6) measures the field of view from the variation of the detected pupil diameter. The characteristic point of the invention is that the display (1) is so constructed that the luminance of the background of the screen and the luminances of the light stimulus targets can be independently adjusted.

Description

technical field [0001] The invention relates to a perimetry for measuring the visual field of a subject. Background technique [0002] An examination of the visual field (ie, perimetry) is done to diagnose shrinkage of the visual field that is a symptom of diseases such as glaucoma. In traditional visual field measurement, the subject's visual field is measured by displaying an eye-target at a specific position in front of the subject's eyes, and then asking the subject to answer whether they see the target. This examination is a subjective examination based on the subject's subjective answer, and the subject's visual field range is determined by measuring the visual field multiple times while changing the display position of the optotype one by one. In such a subjective inspection, there is a problem in that the inspection result is easily affected by the physical condition, concentration, etc. of the examinee, and accurate inspection cannot be performed. In addition, sin...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned traditional perimetry, since the visual target is projected on the screen, or light-emitting diodes are used to display the light-stimulating visual target, there is a problem that the background brightness, the visual target brightness and the visual target size cannot be easily adjusted.

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