Sleep duration and adolescent vision outcomes: evidence from rural China

Objective

To examine the association between weekday sleep duration and visual health among adolescents in low-resource rural settings, and to explore potential behavioral mechanisms.

Methods

We used cross-sectional data from 36,139 rural primary and junior high school students in northwestern China (2012, 2019). Visual acuity was assessed via standardized LogMAR tests. To address potential endogeneity in self-reported sleep, we applied two-stage least squares regression with sunset time as an instrumental variable.

Results

Students averaged 8.65 weekday sleep hours, and 58.3 % slept fewer than 9 h—below age-specific recommendations. Instrumental variable estimates indicated that each additional weekday sleep hour reduced the LogMAR score by 0.070 (p < 0.05), indicating better vision. Mechanism analysis suggested that shorter sleep was linked to greater late-night screen use and near work.

Conclusions

Insufficient weekday sleep is associated with poorer vision among rural adolescents, potentially mediated by digital screen exposure. School-based programs that promote adequate sleep and reduce nighttime screen use may offer a low-cost, scalable approach to support visual health in under-resourced areas.