Commentary on: He M, Xiang F, Zeng Y, et al. Effect of time spent outdoors at school on the development of myopia among children in China: a randomized clinical trial. JAMA 2015;314:1142–8.[OpenUrl][1][CrossRef][2][PubMed][3] The epidemic of myopia has been well-documented in urban East Asia, exceeding 80% in school leavers, with evidence suggesting moderate rises elsewhere.1 Given the strong link between myopia and sight-threatening pathology,1 curbing myopia has become a major topic of public health interest. This has sparked research to identity modifiable factors, with increased time outdoors consistently shown to prevent myopia.2 This randomised control trial is the largest to investigate the efficacy of increasing the time children spend outdoors in the prevention of myopia. Primary schools (n=30) in Guangzhou, China were divided into six strata according to uncorrected visual acuity (VA), … [1]: {openurl}?query=rft.jtitle%253DJAMA%26rft.volume%253D314%26rft.issue%253D11%26rft.spage%253D1142%26rft.atitle%253DEFFECT%2BOF%2BTIME%2BSPENT%2BOUTDOORS%2BAT%2BSCHOOL%2BON%2BTHE%2BDEVELOPMENT%2BOF%2BMYOPIA%2BAMONG%2BCHILDREN%2BIN%2BCHINA%253A%2BA%2BRANDOMIZED%2BCLINICAL%2BTRIAL%26rft_id%253Dinfo%253Adoi%252F10.1001%252Fjama.2015.10803%26rft_id%253Dinfo%253Apmid%252F26372583%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [2]: /lookup/external-ref?access_num=10.1001/jama.2015.10803&link_type=DOI [3]: /lookup/external-ref?access_num=26372583&link_type=MED&atom=%2Febmed%2F21%2F2%2F76.atom