SOME CHARACTERISTICS OF PERIPHERAL VISUAL PERFORMANCE

Abstract

In a 14 point perimetric test for peripheral visual acuity, correlations of individual point scores and groups of scores with the total score did not reveal any point or group of points more reliable than others. This was true of the test scores of both photopic and scotopic acuity subjects. A measure of spontaneous fluctuation or wavering in the response to peripheral visual stimuli was extracted. Visual acuity performance was found to be 78% steady by day and 84% steady at night. Training by controlled practice in 43 subjects yielded a final score which was 334% of the starting score. There was successful transfer of the effects of the training both to other laboratory situations and to conditions of outside life. There was successful transfer of training under photopic conditions to night visual acuity to the extent of 187% of a normal untrained score. A day visual acuity test with time of stimulus limited to 1/5 sec. correlated with night visual acuity scores in the same 42 subjects with a coefficient of 0.62. The intermittent nature of peripheral visual function is thought to be due to temporary multiple scotomata. The peripheral retina is interpreted to be an unpracticed sensory area.