Although refractive error is unaffected by diet, diet has been shown to be important for retinal health. Diets high in fats, cholesterol, along with cigarette smoking or diabetes can lead to an increased risk of age-related macular degeneration (AMD), a potentially blinding disease of the retina. Diets high in vegetables, low in meats, and high in antioxidants (e.g., lutein, &bgr;-carotene, vitamins A, C, and E, zinc, and omega-3 fatty acids) have been shown to be protective for retinal degeneration. The age-related eye disease study (AREDS) formulation, which has been proven effective in numerous clinical trials, includes a specific daily amount of 500-mg vitamin C, 400 IU of vitamin E, 15 mg of &bgr;-carotene (often labeled as the equivalent of 25,000-IU vitamin A), 80 mg of zinc as zinc oxide, and 2 mg of copper as cupric oxide to prevent copper deficiency anemia and is taken with meals in two equally divided doses in the morning and evening. This therapy has been superseded by the AREDS2 formulation, which eliminated vitamin E due to its associated increased risk of lung cancer in smokers and replacing &bgr;-carotene with lutein and zeaxanthin.