In Vivo Density of Cone Pigments after Repeated Complete Bleaches

Abstract

Even short durations of intense light may cause retinal damage, of the sort discussed by Dr. Ham and Dr. Lawwill in their papers for this symposium. (For a general review of light damage see Lanum, 1). One of the authors of the present paper, HDB, has a long history of repeated exposures to intense lights, that occurred during a program of measurements of his cone pigments by the technique of retinal reflection densitometry. In 1963, and again in 1968 he estimates his left eye was totally bleached over 100 times (2, 3). Then, beginning in the early 1970’s the regimen became more regular with approximately 100 total bleaches of his left eye each year; between September and April this year’s count already exceeds 100.