Carotenoids are natural yellow to red pigments that absorb blue light, and are found in foods such as carrots. They are effective in protecting the eye from blue and near-ultra violet radiation and are valuable antioxidants. Four classes of carotenoids in humans (beta-carotene, alpha-carotene, gamma-carotene, and beta-cryptoxanthin) have vitamin A properties. The property of other carotenoids, lutein and zeaxanthin, to absorb blue and near-ultra violet light, help to protect the macula and are therefore especially useful for eye conditions related to problems with the macula such as macular degeneration.
Carotenoids are found within the eye, zeaxanthin predominating in the macula, and lutein predominating in the retina. Foods that are rich sources of lutein and zeaxanthin (in order of amount contained in 1 cup, cooked) include kale, spinach, collards, turnip greens, raw spinach, corn, green peas, broccoli, raw romain lettuce, green beans, two eggs and one orange.
See more about food sources for these and other carotenoids.