We studied the effect of topical anesthesia on infant stress and corneal haze during the routine eye examination for retinopathy of prematurity. Using a double-blind protocol, 55 premature infants weighing less than 1501 g at birth were selected randomly to receive normal saline or proparacaine HCl 0.5% eye drops as a corneal wetting agent at their initial eye examination. Before, during, and after the procedure, infant stress was evaluated by heart rate, respiration rate, blood pressure, and transcutaneous oxygen saturation. Subjective assessment of the infant's cry intensity and corneal haze also were recorded. Adequate data were collected on 42 patients. Using analysis of variance and chi-square tests, we found no difference in any of these parameters between the two patients groups. These data suggest that topical anesthetic agents offer no advantage over normal saline eye drops during the examination of premature infants.