Singlet oxygen as a possible factor in human senile nuclear cataract development.

The effects of photodynamically generated singlet oxygen on lens crystallins were investigated. This highly reactive oxidant can produce in crystallins in vitro the oxidative modifications characteristic of proteins from aging and cataractous lens. Additionally species capable of producing singlet oxygen in the presence of near UV radiation are shown to be present in human lenses. These findings are discussed with respect to a possible role of singlet oxygen in the etiology of human senile nuclear cataracts.