In a new retina/pigment epithelium/choroid preparation developed by Dr. Dennis Dacey at the University of Washington, Seattle, it is possible to obtain high quality, long-term recordings from light-adapted neurons over a period of 12 or more hours. The investigator proposes a collaborative venture with Dr. Dacey to functionally characterize identified interneurons in the primate retina. At present, there are no recordings from primate bipolar cells, amacrine cells, or H2 horizontal cells and nothing is known about their color-coded response properties or general functional characteristics.