Peripheral Visual Acuity

Abstract

Since the classical work of Wertheim¹there have been many studies of peripheral visual acuity. Those published prior to 1951 were thoroughly reviewed by Low.²Data from representative investigations are shown in Fig 1. Only two studies provide any information as to the variability of normal acuity at each eccentric location. Low's paper³on the acuity of 100 normal subjects gives data only for the far periphery, 30°, 60°, and 90° from fixation. Weymouth⁴published values of the mean threshold visual angle and its standard deviation for six locations between fixation and 20°. These are based on records of 20 students in a laboratory course. The mean acuities are, at all tested locations, far below any reported in other studies; for example at the fovea, about 20/40; at 5 degrees in the periphery, 20/200. These low acuities are perhaps to be attributed to the use of