Assessment of acuity of amblyopic subjects using face, grating, and recognition stimuli

For amblyopic subjects, square-wave gratings, such as those used in preferential looking tests of infants' vision, yield more optimistic estimates of visual acuity than complex stimuli such as letters. A complex stimulus--a schematic face pattern--has recently been shown (Harris et al, IOVS 25:782, 1984) to permit preferential looking estimates of acuity of infants with normal eyes. In the present study, older amblyopic subjects had acuities measured with the face stimulus as well as gratings and standard recognition tests. Acuities measured with the face stimulus agreed better with the results of the standard recognition tests than did those obtained with gratings. Thus, if amblyopia of infants and young children affects spatial vision in a manner similar to that of older children and adults, one would anticipate that complex stimuli, such as the face pattern, would complement current assessments of young pediatric patients.