Zeaxanthin is one of the members of the carotenoid family. It is natural fat-soluble yellowish pigment found in some plants, algae and photosynthetic bacteria. From the many carotenoids in the diet, the human retina selectively accumulates only two: Zeaxanthin and Lutein. Their concentration is so high in the macula, (the retinal region responsible for fine visual activities) that the carotenoids are visible as a dark yellow spot called the macular pigment. Because these carotenoids absorb blue light, and because they are powerful antioxidants, scientists have hypothesized that they protect the retina.
Researchers speculate that these carotenoids may promote eye health through their ability to protect the eyes from light-induced oxidative damage and aging through both their antioxidant actions as well as their ability to filter out UV light. Zeaxanthin serves as accessory light-gathering pigments and to protect these organisms against the toxic effects of ultra-violet radiation and oxygen. It also appears to protect humans against phototoxic damage. It is found in the macula of the human retina, as well as the human crystalline lens. It is thought to play a role in protection against age-related macular degeneration (ARMD) and age-related cataract formation. Zeaxanthin may be ophthalmoprotective. Lutein and zeaxanthin, which are naturally present in the macula of the human retina, filter out potentially phototoxic blue light and near-ultraviolet radiation from the macula. It shows some promise of protecting against macular degeneration and may reduce the risk of cataracts in some.
References:
PDR Health. http://www.pdrhealth.com/drug_info/nmdrugprofiles/nutsupdrugs/lut_0164.shtml
MD Foundation Inc. http://www.eyesight.org/Research/Research-Zeaxanthin/research-zeaxanthin.html
http://www.whfoods.com/genpage.php?tname=nutrient&dbid=126
