Bietti's crystalline corneal-retinal dystrophy is characterized by deposits of crystals in the marginal cornea and the paracentral and peripapillary retina. To date, only three cases with long term follow-up have been reported. The case of another patient, who has been observed for 16 years, is reported here. The most striking morphologic feature during the period of examination was the diminution of the retinal crystals, an optical phenomenon that appears to be due to the advanced atrophy of the retinal pigment epithelium. The progressive course is documented photographically.