We developed a reliable method for measuring corneal regeneration in humans with noninvasive, readily available photographic techniques. We then used this method prospectively to compare the rates of primary corneal regeneration after surgery in a series of 27 diabetic and nondiabetic patients. The rates of corneal epithelial regeneration were not significantly different when diabetic patients were compared with nondiabetic patients. A tendency toward recurrent epithelial defects was confirmed in the diabetic patients, however.