Light-induced damage to ocular lens cation pump: prevention by vitamin C.

The cation pump activity of the ocular lens was damaged by exposure to light in the presence of riboflavin phosphate. The intensity of light was similar to that used for reading purposes. The observed light-induced damage was due to superoxide or its derivatives, the superoxide being produced photochemically. Such damage was attenuated by vitamin C in amounts comparable to that in the aqueous humor. Thus, a new role for the high ascorbate level present in the anterior chamber fluid and the lens has been suggested. Ascorbate in other tissues also might have this novel physiological function of protecting against damage due to superoxide and its derivatives produced during normal cellular oxidation.