Guinea pig strain 13 animals, Lewis rats, and non-human primates immunized at a site distant to the eye with the Soluble antigen (S-antigen) of the retina in complete Freund's adjuvant develop experimental allergic uveitis (EAU). Depending on the antigen immunizing dose and the animal, the ocular lesions can vary from an iridocyclitis to a panuveitis. Lymph node cells, nonadherent T-cells obtained from peritoneal exudate cells, and peripheral lymphocytes from immunized animals manifested significant cellular immune responses whether measured by the lymphocyte culturing technique or by evidence of the production of migration inhibition factor (MIF) of macrophages. Ocular electrophysiologic (ERG) alterations seen in non-human primates with S-antigen uveitis are similar to those seen in patients with posterior uveitis. Cyclosporin A, a drug with specific anti-T-cell activity, has been found to be exceptionally effective in preventing the induction of EAU in rats, and in suppressing the inflammation once immunization has occurred.