Oxidative stress can impair the structure and function of connexins (gap junction protein), can modify lens crystallins, and can cause aggregation of proteins, all of which contribute to cataract development. Glutathione is a reducing agent that detoxifies free radicals, thus preventing such damage. It is found in high concentration within the lens and the aqueous. It can be synthesized and regenerated by the lens epithelial cells and young lens fibers. The deeper fibers. Glutathione also has a role in maintaining membrane transport mechanism.
Ascorbic acid also provides some protection to lens epithelium against UV-induced damage to deoxyribonucleic acid (DNA) and is present in relatively high levels in the aqueous humor.