On the evolution of binocular ophthalmoscopy.

The need for stereopsis arose soon after the discovery of the ophthalmoscope, not least because the glaucomatous cup was mistaken for a swelling. At that time, Brewster's popular stereoscope was already in use, and its theory and method were then applied to ophthalmoscopy by Giraud-Teulon. His was the first binocular instrument, subsequently much improved by Zachariah Laurence. Binocular indirect ophthalmoscopy was abandoned toward the end of the 19th century in favor of direct monocular ophthalmoscopy, until it was revived in the 1950s by Schepens.