Light and oxygen are necessary for the function of the eye. However, when present in excess or in uncontrolled circumstances, they appear to be related, probably causally, to the development of cataract. Compromises of function of the lens and retina with aging are exacerbated by depleted or diminished primary antioxidant reserves, antioxidant enzyme capabilities, and diminished secondary defenses such as proteases. Smoking appears to provide an additional oxidative challenge associated with depletion of antioxidants as well as with enhanced risk for cataract formation. Poor education and lower socioeconomic status are associated with poorer nutriture and are also significantly related to increased risk for these debilities. Optimizing nutriture, including diets rich in fruit and vegetables, may provide the least costly and most practicable means to delay cataract.