Fig. 4
From: Refractive errors and visual impairment among children and adolescents in southernmost China
Changes of distribution lines of myopia, hyperopia, astigmatism and the distribution of different SE with age groups. Locally weighted regression lines derived for prevalence of myopia (SE ≤ -0.50D, ≤ -5.00D, ≤ -6.00D), hyperopia (SE*), Significant hyperopia (SE ≥  + 3.00 D) and astigmatism (cylinder*) as a function of age group for Hainan children and adolescents