A purposive literature search will be conducted in the Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), and Health Technology Assessment (HTA) Database via Centre for Reviews and Dissemination (CRD) using the keyword “myopia.” A more comprehensive search strategy will be applied in MEDLINE and EMBASE, using medical subject headings (MeSH) and text words related to spectacles, contact lenses, anti-muscarinic agents, myopia, and children [4, 32]. Database search date is 15 January 2017. For all included studies, reference lists will be also searched. MEDLINE search strategy and keywords are provided in Additional file 2. No language, study type, or date restrictions will be used.