Forty-one patients who had undergone bone marrow transplantation were examined. Nineteen (63%) of the 30 who had received fractionated total body irradiation (TBI) had cataracts in comparison with only 1 (9%) of the 11 non-irradiated patients. No significant differences in steroid therapy were demonstrated between these groups of patients. Dry eyes were observed in eight irradiated patients, seven of whom had preceding graft-versus-host disease. Superficial punctate staining of the bulbar conjunctiva was observed in 25 (83%) of the irradiated group and, in milder form, in five (45%) of the non-irradiated group. Our data suggest that the incidence of cataract following fractionated TBI is influenced not only by the total dose of radiation but also by its rate of administration (defined by midline tissue dose rate and fractionation schedule). In addition dry eyes and conjunctival staining may be exacerbated by TBI, though other aspects of conditioning may also be implicated.