In a detailed investigation of 174 patients who wore patches over both eyes after ocular operations, some 35 per cent were observed to have one or more symptoms of mental aberrations. In a smaller group who had repair of retinal detachment and therefore had to wear eye patches for a much longer time, the incidence of mental symptoms was 100 per cent. A common symptom called "noncompliance" was found which has hitherto been regarded simply as lack of cooperation by the patient. The incidence of postoperative complications was considerably higher in patients who had symptoms of mental disturbance than in those who did not. In these circumstances it would appear worth while to prepare the patient mentally for operation, to give him assurances beforehand, and to take measures to reduce his "isolation" while he has to wear patches.