Zinc is an necessary trace element for all forms of life. This mineral enables vitamin A to create a pigment called melanin, which protects the eye. Zinc is highly concentrated in the eye, usually in the retina and choroid, the vascular tissue layer lying under the retina.
Zinc Eye Benefits
Impaired vision has been associated to zinc lack. Zinc has been shown to protect against night blindness and macular degeneration.
Zinc lack may result in abnormal dark adaptation or night blindness. Zinc works in the eye as a partner to vitamin A. A deficiency of zinc may reduce the activity of retinol dehydrogenase, an enzyme needed to help vitamin A work in the eye. Without zinc, the vitamin A that’s present may not be as efficacious, and night blindness could result. Some doctors suggest 15 to 30 mg of zinc per day to support healthy vision.
Age-Related Macular Degeneration (AMD)
Age-related macular degeneration is a form of macular disease which affects the eye’s retina. This disease is the leading cause of blindness among elderly individuals in the developed world. Findings from the Beaver Dam Eye Study, reported in 1996, show a link between low zinc intake and risk of macular degeneration. The American Optometric Association recommends 40-80 mg of zinc for individuals with early stage AMD or who are at high risk for progression of the disease. This mineral can block the absorption of copper. The American Optometric Association recommends supplements with 2 mg/day of copper for people taking zinc.
A large, randomized, placebo-controlled, clinical study, older participants with age-related macular degeneration (AMD) who took a daily dietary supplement with 80 mg zinc, 2 mg copper, 400 IU vitamin E, 15 mg beta-carotene, and 500 mg vitamin C for approximately 6 years had a lower chance of developing advanced AMD and less vision loss than those who did not take the dietary supplement. In another study, in 74 age-related macular degeneration patients reported that supplement with 50 mg/day of zinc monocysteine for 6 months improved measures of macular function, including visual acuity, contrast sensitivity, and photorecovery.