Singlet Oxygen in the Eye
Singlet oxygen is one of the naturally occurring reactive oxygen species that increases in the human eye with age. The reason for the increase in this reactive oxygen species is the age-related chemical change of photochemically inactive to active tryptophan derivatives in the lens and accumulation of photochemically active lipofuscin in the retina. Singlet oxygen may also be produced in the eye in the presence of ambient radiation with phototoxic drugs, herbs and nanoparticles. Although singlet oxygen damages the eye, it can also be used to treat ocular disease. Using the proper sunglasses and appropriate singlet-oxygen quenchers may limit the singlet oxygen damage to the eye.