There have been greater advances in our knowledge of the visual function and its disabilities in the past 50 years than had accumulated in all of the previous years. This applies not only to the basic science of biochemistry, physiology, physiopathology, and cytopathology but also to the diagnosis and treatment of visual dysfunction and ocular disease. These advances have been aided by a proliferation of ingenious instruments. When I began my residency in ophthalmology at The Wilmer Institute in 1938, one was supposed to learn not only the physiology of vision but also how to diagnose and...