The aim of this study was to determine, in infants born at < or =29 weeks postmenstrual age until 32 weeks postmenstrual age, whether reduction to light stimulation by occlusion of eyes affected central visual development. The pattern visual-evoked potential responses at 41 and 51 weeks postmenstrual age and 3 y of age did not differ between infants subjected or not to ocular occlusion. Hence, an early marked reduction in light stimulation in preterm infants does not seem deleterious to visual development.