You’ve probably heard that lutein and zeaxanthin are good for the eyes. These two major carotenoids found in the macula and retina are sometimes called xanthophylls or macular pigment. They function as antioxidants and also help protect tissues from phototoxic damage by filtering out some of the blue light.
The eye, and particularly the macula and retina, are almost constantly subjected to free radical generation and oxidative damage. Just as exposure to too much sunlight can damage the skin, so too can light damage the eyes. It is, thus, critical that you maintain your basic nutrients and especially antioxidants in the eye.
A study of macaque monkeys (with eyes similar to humans) showed that there was more zeaxanthin than lutein in the central fovea where vision is most clear. But, the concentration of zeaxanthin is reduced the further you get from the fovea and lutein dominates.
The macula has a yellow tint due to the presence of lutein, zeaxanthin and another xanthophyll called meso-zeaxanthin. It’s these pigments that help filter out or absorb some of the more damaging blue light to help protect the eye.