Visual acuity in a national sample of 10 year old children.

The prevalence of defects of visual acuity among the 10 year old children in the 1970 birth cohort was 22.1%, but only in one third of these children was the defect more severe than 6/9. Defects were more common among girls. The relation of defects to social class was complex. Comparison with data collected on the children of the 1958 cohort when they were 11 years old suggests that although the prevalence of 6/9 visual acuity has remained constant over the last decade, the prevalence of more severe defects has declined from 12.9% to 7.3%. These findings have a number of implications for the provision of screening programmes and of ophthalmic services for children.