A new clinical study led by the National Eye Institute (NEI), part of the National Institutes of Health, will follow 500 people over five years to learn more about the natural history of age-related macular degeneration (AMD). Using the latest technology to visualize eye structures and measure their function, researchers hope to identify biomarkers of disease progression, long before it progresses to advanced disease and results in vision loss. AMD is the leading cause of visual impairment and blindness in people age 50 and older in the United States.