Age-related macular degeneration (AMD) is the leading cause of irreversible blindness and moderate visual impairment in older, white persons (1–11) and will remain a major threat to vision in coming decades (12,13). AMD research has progressed substantially in the last quarter of the 20th century and provides clues for future research directions (12,14–27). Although the exact etiology of AMD remains uncertain (12), we now have a considerably better understanding of this condition than 30 yr ago. The purpose of this chapter is to summarize progress on understanding the epidemiology of AMD in the last two to three decades.