Myopia in children has dramatically increased worldwide. A systematic review and meta-analysis were conducted to evaluate the effects of outdoor light exposure on myopia. According to research data from 13 studies of 15,081 children aged 4–14 at baseline, outdoor light exposure significantly reduced myopia incidence/prevalence (odds ratio [OR] = 0.85, 95% confidence interval [CI]: 0.80–0.91, p < 0.00001; I2 = 90%), spherical equivalent refractive error (SER) by 0.15 D/year (0.09–0.27, p < 0.0001), and axial elongation by 0.08 mm/year (−0.14 to −0.02, p = 0.02). The benefits of outdoor light exposure intervention, according to pooled overall results, included decreases in three myopia indicators: 50% in myopia incidence, 32.9% in SER, and 24.9% in axial elongation for individuals in Asia. Daily outdoor light exposure of more than 120 min was the most effective intervention, and weekly intervention time exhibited a dose–response relationship with all three indicators. Subgroup comparisons revealed that interventional studies report greater benefits from outdoor light exposure compared with cohort and cross-sectional studies, and individuals with myopia in intervention studies experienced slightly greater benefits than individuals without, in terms of SER and axial elongation. Therefore, this study suggests 120 min/day of outdoor light exposure at school.

Aim: To investigate the protective behaviours of longer near work distance, discontinuing near work and more time outdoors in recess from parent self-report in the myopia prevalence and progression among myopic children aged 9–11 years.Methods: Myopia Investigation study in Taipei is a longitudinal population-based study that enrolled elementary school students in Taipei. We provided vision and refraction examination every 6 months. Spherical equivalent (SE) of cycloplegic refraction ≤−0.50 Diopter (D) is defined as myopia. Total 10 743 (70.4%) students completed 2-year refraction data and questionnaire. The myopia prevalence and progression (difference of SE) in baseline, 6, 12, 18 and 24 months were compared by generalised estimating equations.Results: Children with persistent protective behaviour had significant lower prevalence of myopia. The protective impact was statistically significant from 6 to 24 months. In 2 years follow-up, risk ratio after adjusting the background variables and the other two behaviours in near work distance, near work time and outdoor time were 0.71, 0.89 and 0.77. In SE analysis, after adjusting the other two behaviours, near work distance >30 cm (−0.7 vs −1.04 D; p<0.001), discontinuing near work every 30 min (−0.77 vs −0.96 D, p=0.005) and more time outdoors in recess from parent self-report (−0.75 vs −0.98 D; p=0.012) revealed protective impacts on diminishing myopia progression from 6 to 24 months.Conclusion: In myopic children aged around 10 years in Taipei, longer distance in near work, discontinuing near work every 30 min and more outdoor time from parent self-report are protective behaviours in myopia prevalence and progression in 6–24 months.