322 children who were suffering from either spina bifida or hydrocephalus were examined over a six year period. Regular examinations were made of visual acuity and field, ocular motility and fundus starting at the time of birth or diagnosis and repeated, whenever possible, at each clinic visit or hospital admission. A particular effort was made to see children about to have exploratory surgery for suspected shunt dysfunction or raised intra-cranial pressure to determine the frequency of positive eye findings in such cases. Ophthalmic complications were found to be very common in the children studied. 136 (42%) had a manifest squint, 93 (29%) a lateral rectus palsy or musculo-paretic nystagmus, 44 (14%) had papilloedema and 55 (17%) had optic atrophy. Only 86 (27%) definitely had normal visual function. 70% of proven episodes of shunt dysfunction had positive ophthalmological evidence of raised intracranial pressure. The presence of an ophthalmologist in the spina bifida and hydrocephalus clinic was increasingly valued as the study progressed. Every spina bifida and hydrocephalus clinic should have an ophthalmologist in its medical team. He should undertake regular examinations of visual acuity and field, ocular motility and fundi, starting at the time of birth or diagnosis, and tailor ophthalmic care to the special needs of these children. This should ensure that these children achieve and maintain the best possible standard of vision and that the earliest ophthalmic signs of raised intracranial pressure can be detected in patients where the diagnosis is in doubt.