Outdoor activity, screen time and sleep associated with myopia in Chinese schoolchildren

A cross-sectional study published in BMC Public Health examined associations between lifestyle factors and myopia among 8,762 students aged 6–18 years in Leshan, China. Participants were recruited using multistage stratified random cluster sampling from May to November 2025. Myopia was defined as spherical equivalent refraction below −0.50 diopters in at least one eye, measured by non-cycloplegic autorefraction. Questionnaires assessed outdoor activity, screen exposure, sleep duration and potential confounders.

Myopia prevalence was 76.19%. In multivariable logistic regression, more than one hour of daily outdoor activity was associated with lower odds of myopia (OR 0.849, 95% CI 0.766–0.942). Screen time exceeding two hours daily (OR 1.135, 95% CI 1.022–1.259) and insufficient sleep (OR 1.139, 95% CI 1.032–1.257) were associated with higher odds. The supplied report did not specify the threshold for insufficient sleep.

These findings identify lifestyle correlates potentially relevant to childhood myopia prevention, but cannot establish whether changing these behaviors prevents myopia. Interpretation is limited by the cross-sectional design, questionnaire-based exposure assessment and non-cycloplegic refraction. Longitudinal studies are needed to clarify causal relationships. The authors reported no specific funding and no competing interests.