Spatial altitude factors on the association with myopia: a narrative review

Myopia has emerged as one of the most pressing global public health challenges, characterized by rapidly increasing prevalence, earlier onset, and growing risk of vision-threatening complications. While genetic susceptibility contributes to refractive development, accumulating evidence indicates that environmental exposures play a dominant role in shaping ocular growth trajectories. Spatial altitude represents a unique ecological exposure integrating hypobaric hypoxia, enhanced solar radiation, distinctive climatic conditions, and lifestyle patterns. Epidemiological observations consistently demonstrate lower myopia prevalence among high-altitude populations compared with lowland regions, suggesting potential protective environmental influences. This review synthesizes current epidemiological findings and mechanistic hypotheses regarding altitude-associated differences in refractive status. We discuss potential pathways involving light-induced dopaminergic signaling, hypoxia-mediated molecular regulation, behavioral adaptations, circadian synchronization, and gene-environment interactions. We further highlight limitations of existing evidence and propose future research directions integrating environmental monitoring, longitudinal cohort studies, and multi-omics approaches. Understanding altitude-related influences on ocular growth may provide novel insights into environmental interventions for myopia prevention and contribute to strategies addressing the global myopia epidemic.