• A 41-year-old man, referred because of the suspicion of retinal detachment, was found to have retinoschisis, moderately severe renal disease, and adult cystinosis with crystals in the cornea and conjunctiva. Conjunctival crystals were demonstrated by light and electron microscopy, and chemical analysis confirmed the presence of excessive amounts of cystine. Studies of renal tissue showed changes that were interpreted as being due to hypertensive vascular disease. Light and electron microscopic examination of kidney tissue showed no cystine crystals, and chemical analysis indicated only trace amounts of cystine.