In seven patients who each had either a methyl methacrylate corneal shell, a postenucleation ocular prosthesis, or a keratoprosthesis, giant papillary conjunctivitis of the tarsus of the upper lids developed after prolonged wear. These cases expand the spectrum of disease that was initally described in wearers of hard and soft contact lenses. The papillary changes in prostheses wearers did not always produce symptoms and were not readily reversible. Basophils and mast cells characterized the inflammatory infiltrate, suggestng an antigen-antibody mechanism underlying the response. Increased production of epithelial mucin, in contrast to goblet cell mucin, may play a role in producing symptoms in this syndrome.