This study investigated the extent of infant peripheral vision, specifically the extent of infants' constricted field, or tunnel vision. Thirteen infants, 2 to 5 months old, were tested using a psychophysical procedure to obtain contrast sensitivity thresholds at four retinal loci (-40, -15, +15, +40 deg.). Infants were placed in an infant bed in a dark room and presented first with a central fixation light, then a stimulus either to the right or left of the infant's fixation at 40 degrees eccentricity according to a random schedule. If the infant responded with directionally appropriate first eye movement occurring within three seconds of the termination of the stimulus, the intensity was decreased by .1 log unit steps until the response was no longer observable. Then the intensity was increased by .5 log unit steps until the response reappeared. Following this, the intensity was decreased using .1 log unit steps until the boundary was determined. The threshold values were taken as the minimum light tensity that would reliably elicit the response. Intensity changes were made independently for the left and right stimulus lights. Threshold measures for the 15 degree eccentricity were obtained in the same manner. Data indicated that infants are less sensitive to a peripherally presented point source than adults, the differences being greater in magnitude for the far targets than for the near targets. However, infants in this study were found to be capable of detecting targets farther in the periphery than previously realized, provided the target was sufficiently bright. The effectiveness of the methodology used is discussed. (SB)