Eating plenty of fruits and vegetables also keeps your eyes in good shape. You may have learned that the vitamin A in mangoes, oranges and tomatoes aids night vision. Other fruits and vegetables help prevent two common aging-related eye diseases - cataract and macular degeneration - which afflict millions of people over age sixty-five. Cataract is the gradual clouding of the eye's lens. The lens is a disk of clear protein that focuses light on the light-sensitive retina. Macular degeneration is caused by cumulative damage to the macula, the centre of the retina. It starts as a blurred spot in the centre of what you see. As the degeneration spreads, vision shrinks.

Free oxygen radicals generated by sunlight, cigarette smoke, air pollution, infection, and metabolism cause much of this damage. Dark green leafy vegetables and dark fruits contain two pigments, lutein and zeaxanthin, that accumulate in the eye. These two appear to be able to remove the free radicals before they can harm the eye's sensitive tissues.

In general, a diet rich in fruits, vegetables, and whole grains appears to reduce the chances of developing cataract or macular degeneration.