Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in the United States and other western nations. Limited treatment is available, and there are no established means of prevention. The detection of modifiable risk factors is important to suggest preventive behaviors that can reduce disease occurrence or prevent the progression to the late stages of AMD. Results of recent studies suggest that the etiology and pathogenesis of AMD are a complex interaction of genetic and external factors. Although a number of factors seem promising, only age and cigarette smoking are confirmed as increasing AMD risk. Other factors that most likely play a significant role in AMD are nutritional factors, e.g., antioxidants, and hypertension or other underlying atherosclerotic disease processes. The results of the Age-Related Eye Disease Study suggest a moderate beneficial effect of antioxidant, vitamin, and zinc supplementation in reducing progression to severe AMD.