Lutein There is a growing body of evidence that lutein, a non-pro-vitamin A carotenoid pigment naturally found in plants, plays an important role in human health. The rationale for the protective role of lutein in the body stems from the ability of this carotenoid to: 

filter harmful short-wavelengths of visible light (i.e. blue light), 

function as antioxidant 

stabilize membrane integrity. 

These biological functions allow lutein to reduce the number of free radicals generated in the body directly by filtering blue light filter, or indirectly by working as an antioxidant. Lutein deposited in almost all the structures of the eye and is selectively concentrated in the macula lutea, the region of the retina responsible for central vision. Several studies have shown that incidences of AMD can be reduced by consuming diets with high levels of lutein and supplementation by increasing their concentration in serum and parallel increase in macular pigment optical density (MPOD). MPOD is a measurement of the attenuation of blue light by the macular pigment and is linearly related to the amount of lutein in the macula. Lutein is not synthesized by the body and thus must be ingested as part of the diet in order for it to be utilized. Marigold and dark green leafy vegetables like spinach and kale are the richest sources of lutein.

Vitamin C exists at high levels in the retina and is very efficient for protection against diseases that involve oxidative stress. Studies suggest long-term consumption of vitamin C also may reduce the risk of forming a cataract and vision loss from macular degeneration. Vitamin C also promotes healthy blood vessels including the delicate capillaries in the retina.

Vitamin E Typically, vitamin E acts as a chain-breaking antioxidant, which prevents the propagation of free radical damage to lipids in biologic membranes. The RPE and the outer segments of the rods in the retina are rich in vitamin E, which is important in protecting the retina from oxidative injury. Several research reports show that the antioxidant properties of vitamins C and E may protect against the development and progression of cataracts.

Zinc is required as a cofactor by more than 100 enzymes in the eyes, skin, muscles, bones, kidneys, and other organs. It was found that zinc deficiency may be implicated in the high prevalence of cataract formation. The incidence of cataract development is more common in tropical countries due to the pronounced exposure to sunlight, and zinc has the ability to protect the lens of the eye from oxidative damage. Researchers discovered that taking zinc, along with various other antioxidants, could lower the risk of developing advanced age-related macular degeneration.

Copper has a variety of health benefits, including improving eye health and helping to inhibit the progression of advanced age-related macular degeneration. Copper, acting as an antioxidant, encourages the development of flexible connective tissue for proper eye structure. It binds with zinc, and the two should be supplemented together. On the other hand, Copper is added to eye formulas to prevent copper-deficiency anemia, which can occur if large amounts of zinc are consumed.