Lutein belongs to the carotenoid family of antioxidants. Lutein has been found in the eye, brain, breast, and cervix. In the eye, it is found in the retina, ciliary iris bodies, and lens, but mostly it occurs in the macular region. Increased serum levels of lutein can increase macular pigment density, which helps to quench free radicals that result from photo-oxidation by enhancing the filtering of blue light.