Cataract and AMD are two of the most important causes of visual impairment in older Americans. Approximately 3.3 million people have visual impairment due to cataract. Cataract extraction, although one of the safest and most successful of all operations, is now the most frequently performed operation in the United States among persons older than 60, costing an estimated $1.5 billion annually. AMD is the leading cause of new cases of blindness in persons aged 65 and older. Approximately 25 percent of persons aged 65 years and older have signs of AMD. The pathogenesis of AMD, however, is only partly understood, and its etiology remains obscure. For most patients, there is no available treatment. The public health burden imposed by cataract and AMD will only increase in the coming decades as the U.S. population ages.