Lutein is a xanthophyll and one of 600 known naturally-occurring carotenoids. Found in green leafy vegetables such as spinach and kale, lutein is employed by organisms as an antioxidant and for blue light absorption. Lutein is also found in egg yolks, animal fats, and the retina (zeaxanthin predominates at the macula lutea while lutein predominates elsewhere in the retina).
