Myopia Prevalence Among 6-17 Years Students in Rural Areas of Seven Provinces of China

Background/Objectives: Estimate the prevalence of myopia among children aged 6-17 years in county and rural areas across seven geographically diverse provinces of China, and identify demographic, behavioral, and geographic factors associated with myopia, with particular focus on urban-rural and ethnic differences. Methods: A multi-stage stratified cluster sampling design was employed. Seven provinces were randomly selected, one from each of seven geographical regions of China (Southeast, North, Central, South, Southwest, Northwest, and Northeast). In each province, one rural county was randomly chosen. Within each county, one urban survey site (county town) and one rural survey site (village) were selected. From each site, one primary school and one junior high school were included. In each school, approximately 20 ± 2 students per grade (grades 1-9) were recruited. Uncorrected visual acuity and non-cycloplegic autorefraction were measured. Multivariable generalized linear mixed models (GLMM) with random intercepts at the class level were used to identify factors associated with myopia, accounting for the cluster sampling design. Results: The overall myopia prevalence was 42.9% (urban 49.6%, rural 36.0%). In the multivariable GLMM, educational stage was the strongest risk factor (grades 7-9 vs. 1-3: OR = 5.54). A significant district × ethnicity interaction was found only for Mongolian children: rural residence was strongly protective (OR = 0.19) compared to Han (OR = 0.65), and the ethnic advantage disappeared in county towns. Only 14.2% of myopic students had adequate correction. Conclusions: In conclusion, myopia is highly prevalent and severely under-corrected in rural China. Educational pressure is the main risk factor, and the rural protective effect is strongest in Mongolians but erodes with urbanization. Urgent public health actions, including vision screening, affordable spectacles, and lifestyle preservation, are needed to address this growing burden.