Light damage in the developing retina of the albino rat: an electroretinographic study

The albino rat retina is severely damaged by exposure to bright light. The degree of damage depends upon the intensity of the exposure and its duration. In the present study, electroretinographic (ERG) responses were measured in rats exposed at different ages during the period of retinal development to 24 hr of bright light and then transferred to darkness for about 2 months. The ERG data indicated that if the bright-light exposure was done prior to 20 days of age, the retina was resistant to the light damage, and the dark-adapted ERG responses measured later were normal. In rats older than 20 days, light damage increased with age until, in rats exposed to light at age 30 days, the ERG was unrecordable. Further experiments showed that light exposure did damage the 15-day-old rat retina; however, complete recovery was attained within 15 days postexposure.