The purpose of this study was to provide an account and assessment of screening for vision and hearing defects in pre-school children, concentrating on the role of the health visitor. In particular, the objectives were: 1. To investigate the nature of vision and hearing defects found in school entry children with no previous eye or ear referrals; 2. To test the hypothesis that these children had received a pattern of attention from pre-school health services which differed from a matched `normal' group; 3. To provide an accurate account of the uptake of pre-school screening tests. Variables Nature of vision and hearing problems, maternal age, social class, birth order, clinic attendance, Health Visitor home visits, uptake of pre-school screening tests, health sector, birth weight, waiting time for appointments.