Effects of short‐term low intensity light on the albino rat retina. An electron microscopic study (1)

Retinas of albino rats exposed to continuous, low intensity fluorescent light for periods of 6, 12, and 18 hr display fine structural changes in both pigment epithelial cells and in the outer segments of the photoreceptor cells. Adjacent pigment epithelial cells showed wide intercellular spacing (600 to 36,000 A) and retraction of the villous processes. As the rats were exposed to increasingly longer photoperiods, the lamellated discs, which are flattened in dark‐adapted retinas, became progressively more tubular.