Eating plenty of fruits and vegetables also keeps your eyes in good shape. You may have learned that the vitamin A in carrots aids night vision. Other fruits and vegetables help prevent two common aging-related eye diseases—cataract and macular degeneration—which afflict millions of Americans over age 65. Cataract is the gradual clouding of the eye’s lens, a disk of protein that focuses light on the light-sensitive retina. Macular degeneration is caused by cumulative damage to the macula, the center of the retina. It starts as a blurred spot in the center of what you see. As the degeneration spreads, vision shrinks.
Free radicals generated by sunlight, cigarette smoke, air pollution, infection, and metabolism cause much of this damage. Dark green leafy vegetables—such as spinach and kale—contain two pigments, lutein and zeaxanthin, that accumulate in the eye; these pigments are found in other brightly colored fruits and vegetables as well, including corn, squash, kiwi, and grapes. (12) These two pigments appear to be able to snuff out free radicals before they can harm the eye’s sensitive tissues. (13)
In general, a diet rich in fruits and vegetables appears to reduce the chances of developing cataract or macular degeneration. (14–17) Lutein and zeaxanthin, in particular, seem protective against cataract.