The association between schoolchildren intelligence and refractive error.

PURPOSE: The relationship between refractory errors and intelligence and the importance of genetic, regional and environmental factors in such associations, were investigated in a group of school children. SUBJECTS AND METHODS: One hundred and thirty-seven students (34.3% boys and 65.7% girls) from two primary schools were enrolled in the study. Cycloplegic refraction was performed and a spherical equivalent (SE) > or = 0.5D were determined as hyperopia; <-0.5D myopia and <1 cyl D astigmatism. Demographic factors, parent's education level, teacher based assessment of school performance and average score were also evaluated. RESULTS: Seventy-eight (56.9%) of subjects showed a form of refractory error; 27%, 3% and 2.9% were myope, hyperope or astigmat, respectively, whereas 12.4% of them had both myopia and astigmatism and 10.2% showed hyperopia and astigmatism; 43.1% were normal. CONCLUSIONS: Although our data revealed no distinction of average score between normal group and myopia, hyperopia, astigmatism or hyperopia-astigmatism, there is a statistically significant difference between normal group and those who had both myopia and astigmatism in which the later had a lower mediocre. Our results is somehow in contrast with other parallel studies demonstrating that positive connection between school performance and myopia can be explained by the geographical or racial discrepancies as well as subjects involved in the study and divergent set of cut off limits.