Abstract With the increasing prevalence of light at night (LAN) exposure amid urbanization, children and adolescents have become a particularly susceptible population due to their physiological and behavioral characteristics. Based on a clear definition of LAN, its sources, and assessment methods, the review summarizes epidemiological evidence linking LAN with multi system health outcomes in children and adolescents, including sleep, metabolism, mental health and behavioral problems, vision, cellular senescence, and cancer. Future research should prioritize standardized exposure assessment, multicenter prospective cohorts, and behavioral intervention strategies.