Vision, Visual Acuity, and Ocular Refraction of Young Men

Abstract

A sample consisting of 1,033 young men called up for National Service showed that some 60% of eyes and 70% of young men have unaided vision of 6/6 or better, while vision only slightly below this, 6/7.5, is found in another 12 to 15%. In the general population over 80% of young men can therefore be regarded as having full vision unaided by glasses. Only 4% have unaided vision of 6/60 or less. With correction the incidence of vision of less than 6/7.5 is 3%; only 0.4% of young men have corrected visual acuity of 6/18 or less. The range of ocular refraction in this series extended between + 10 D and —13 D. Some 75% of eyes and of men showed refraction between 0 and +2 D; some 9% showed myopia of up to 4 D, and 2% myopia in excess of this. In all, some 90% of the population have a range of refraction between -1 D and +4 D. Nearly 20% of the population has astigmatism in excess of 0.5 D, fairly evenly divided between astigmatism of 0.6-1 D and astigmatism in excess of 1 D. The higher degrees of astigmatism were not yoked to the higher degrees of spherical errors, but were proportionately distributed over the whole range of refractions. Some 4% of the population showed squint, and 0.5% showed amblyopia ex anopsia of a severe type (6/36 or less). The curve of distribution of ocular refraction gives little support for the widely held view that there is an excess of myopia as distinct from an elongation of the myopic tail. Judged against a Normal distribution, there is a marked excess of emmetropic and near-emmetropic eyes—an excess that eliminates the belief that the individual components of refraction vary freely. The eye is obviously a correlated organ. On the available data at least 15% and possibly as much as 25-30% of men require optical attention during early adult life. © 1960, British Medical Journal Publishing Group. All rights reserved.