Fig. 2From: Refractive errors and visual impairment among children and adolescents in southernmost ChinaDistribution map of three visual acuity groups. Abnormal UCVA: worse than 20/25 (≥ 6, < 8 years old) and worse than 20/20 (≥ 8 years and older) at least in one eye a. UCVA worse than 20/40 b. Mild PVAI c. Moderate PVAI d. Severe PVAI eBack to article page