Purpose: The aim of the paper was to study the prevalence of myopia, hyperopia and astigmatism in schoolchildren ranging from 6-18 years of age.
Material and methods: 5724 children from elementary schools, junior high schools and high schools were examined (2765 boys and 2959 girls, aged 6-18 years, mean age 11.7, SD = 3.2). The examined students were Caucasian and resided in and around Szczecin, Poland. The examination included retinoscopy under cycloplegia. The refractive error readings were expressed as the spherical equivalent (SE). Myopia was defined as SE of at least -0.5 D, hyperopia as SE of at least +1.0 D. Astigmatism was diagnosed when the difference in the refraction of axes in one eye was greater than 0.5 DC. The statistical analysis of data was performed by calculating the linear correlation coefficients and the coefficients for the regression equation. Additionally, Spearman's rank correlation coefficient was calculated. P values of less than 0.05 were considered statistically significant.
Results: It was observed that 13% of Polish students in the age group from 6 to 18 were myopic, 38% of students were hyperopic and 4% were astigmatic. Besides, a positive correlation was found between the prevalence of myopia and age (p <0.001) as well as a negative correlation between prevalence of hyperopia and age (p < 0.001). An association between the prevalence of astigmatism and age was not observed.