The damaging effects of light on the retina. Empirical findings, theoretical and practical implications.

Light well below the intensity which causes thermal burns physiologically damages the retina. This damage is primarily localized in the receptors. The outer segments are most sensitive and slow recovery is possible if damage does not proceed to destruction of the inner segment. Many variables affect the extent and severity of light damage. Damage is correlated with continuity of source, light intensity, elevated body temperature, nocturnality, and albinism. Light damage has been considered only minimally in visual research with light preferences, reinforcement and discrimination, or in clinical settings. Based on the available evidence, it is suggested that retinal damage may be produced by such common light sources as room lighting, phototherapy techniques, ophthalmoscopes and fundus cameras. Further studies are recommended.