The Relationship between Myopia and Intelligence Score among High School Students: A Multicenter Epidemiological Study

Several studies have shown that the prevalence of myopia increases with education. There is lack of studies among adolescent to confirm this link. The aim of this study was to compare IQ score between high school students with and without refractive errors. This cross-sectional study was conducted on 392 high school students (four groups) from ten high schools in Ahvaz in 2016. The participants were divided into four groups including myopia (n=98), hyperopia (n=98), spherocylander (n=98), and normal (n=98). The IQ score had been compared between groups. The intelligence score was measured using two tests including Raymond Bernard Cattell’s test and Raven’s Progressive Matrix test. The mean age of students was 15.3 ± 0.9 yr. Of 392 students, 187 (47.7%) were boys and 205 (52.3%) were girls. The highest frequent IQ score was borderline in three groups, except the most frequent IQ score in normal group was poor. The Mann-Whitney test showed that the IQ score was significantly higher in myopia group and hyperopia group in compare to normal group (P value=0.002 and 0.036, respectively). While, there was no significant difference between spherocylander and normal groups (P value=0.104), myopia and hyperopia groups (P value=0.3), myopia and spherocylander groups (P value= 0.17) and hyperopia and spherocylander groups (P value=0.68) in terms of IQ score. We found significant higher IQ score in myopia group in compare to normal group.