A developmentally based programme (PVD) to promote the visual development of babies with severe visual impairment was evaluated in 58 infants aged between one month and 13 months of age. Progress in nine aspects of visual development was significantly greater for babies receiving the programme. This benefit extended to those with severe learning disability, or with minimal or apparently no vision at entry. The PVD favourably influenced visual outcome when introduced at any time during the first 13 months of life, although earlier introduction enabled greater benefit to be derived from the improved vision. Therefore, it is recommended that infants are referred to a developmental centre as soon as severe visual impairment is suspected.