Refractive state in Adult with Normal Visual Acuity

Cho, Byung Joo

Abstract

Visual acuity refers to the spatial limit of visual discrimination. It is surely the single most significant measure of functional integrity of the eye. Normal visual acuity can be represented in hyperopia of less than 2 diopters or astigmatism of less than 1 diopter. The purpose of this study was to observe the prevalence, type and degree of of refractive errors in 338 eyes of 40-69 years of age with normal visual acuity(20/20 or more). The results were as follows: 1. In objective manifest refraction, 246 eyes(72.8%) had refractive error such as hyperopia(110 eyes), simple hyperopic astgmatism(61 eyes),compound hyperopic astigmatism(57 eyes) and simple myopic astigmatism(18 eyes). 2. In subjective manifest refraction, 132 eyes(39.1%) had refractive error such as hyperopia(51 eyes), simple hyperopic astigmatism(44 eyes), simple myopic astigmatism(24 eyes) and compound hyperopic astigmatism(13 eyes). 3. As to the type of astigmatism, 71 of 81 astigmatism were "against the rule" and the rest(10 eyes) "with the rule". Degree of astigmatism was less than 1.00 diopter. 4. A verage degree of refractive errors was 0.43 diopter.