INSTRUMENTS AND TECHNICS FOR THE CLINICAL TESTING OF LIGHT SENSE

Abstract

One of the most fundamental problems of physiologic optics is the study of the light sense, or achromatic sensitivity of the eye, and in particular the increase in sensitivity which occurs when the eye is exposed to darkness. The term photopic vision is used to designate the condition of the eye when exposed to bright light; scotopic vision, to designate the condition of the eye when exposed to darkness or to a very dim illumination. It is generally believed that photopic vision is dependent chiefly on the retinal cones and scotopic vision on the rods. In the usual ophthalmologic examination the subjective tests include determination of the central visual acuity and examination of the visual fields with white and colored test objects. Study of the visual fields with white test objects is essentially a somewhat crude method of testing the light sense throughout the retina. Since, however, this and the