Sex differences in refraction errors up to the age of 15.

A health inquiry concerning vision and corrective lenses at the age of 14 was carried out in a northern Finland series about 12,000 children followed up since birth. Data were obtained from more than 99% of cases. 34% of the girls and 18% of the boys had corrective lenses. 55% of the study population were living in the province of Oulu, and the ophthalmological records of these children were analysed (N 1939). The ophthalmological records covered 67% of the children with lenses in the province of Oulu. 71% of the girls with lenses, and 66% of the boys had these for myopia, both myopia and hyperopia were less common among the boys, but the cases were more pronounced. The children with lenses were on average taller and heavier and the myopic children had a better mean ability at school.