Visual functions were examined in 18 survivors of perinatal hypoxia/ischemia with mild to severe neurological sequelae, aged between 3 months and 17 years, and in two patients, aged 8 and 13 years, who had suffered postnatal hypoxic events. All but two patients showed clear visual deficits ranging from mild defects in visual acuity, visual field size, and/or optokinetic nystagmus to blindness. In 5 patients, the visual field was restricted to tunnel vision, a finding which appeared to be specifically related to the hypoxic/ischemic nature of the brain damage. The severity of the visual defects after perinatal hypoxia was related to the occurrence of neonatal seizures, later neurological outcome, and gestational age at birth. This is discussed in relation to previous studies of the effects of perinatal hypoxia/ischemia.