The medical records of 224 children who had lens surgery performed at the Hospital for Sick Children during the 10-year period 1978-88 were reviewed. There were 12 children with ectopia lentis; these patients achieved a mean postoperative acuity of 0.68 (6/8.8), and no operative or postoperative complications were noted. Two hundred and twelve children had lens surgery for cataracts or for retrolental abnormalities with a clear lens. Children with bilateral congenital cataracts achieved a mean acuity in the better eye of 0.32 (6/18). In a series of carefully controlled unilateral congenital cataracts the visual results were poor. The postoperative complication rate for cataract and clear lens surgery was 4.6%. Because visual results are probably better with early surgery we emphasise that every newborn baby should be tested for media opacities.