Lutein is one of the caroteinoid antioxidants. Lutein is the main carotenoid present in the middle part of the retina of the eye known as the macula. One of the functions of lutein is to protect the macula from damage by sunlight, a sort of natural sunblock. This protection of the macula by lutein may help prevent the degeneration of the macula that is associated with aging, thus keeping our eyesight in good condition. Acting as an antioxidant, lutein also neutralizes free radicals that can damage the eye. This free radical damage in the eye is thought to eventually play a role in the opaque build-up of damaged protein in the lens of the eyes resulting in obscured vision. Thus, lutein supports good eye health and good vision in many ways. 20 mg. 30 Capsules.