Follow age-appropriate screen limits, while recognizing the limits of the evidence
China's cited guidance recommends no screen devices at ages 0–3, avoiding them as far as possible at ages 3–6, and no more than 15 minutes per session or one hour daily for schoolchildren's recreational use. Its rationale includes prolonged close viewing and early myopia. Research linking screens specifically to myopia is less conclusive than the outdoor-time trial in entry 4.
What it takes
Nothing. Enforcing limits and modeling them yourself can take sustained effort.
What you may gain
Item 4 of China's Ten Key Facts advises against phones, tablets, computers, and similar screens for ages 0–3; minimizing exposure at ages 3–6; and limiting non-learning screen use in schoolchildren to 15 minutes per session and one hour daily. It identifies prolonged close viewing as a contributor to loss of hyperopic reserve and early myopia. The 2018 eight-department implementation plan gives similar parental guidance and says younger children should have shorter uninterrupted use. A systematic review of 33 studies, 11 included in meta-analysis, covered ages three months to 33 years. Smartphone and tablet use had a myopia OR of 1.26, 95% CI 1.00–1.60, I²=77%; combined with computer use, OR was 1.77, 1.28–2.45, I²=87%. The authors described a possible association and reported that none of the 33 studies reliably measured screen time.
Context & considerations
Evidence is B because these age bands are official guidance rather than limits established by an experiment. The smart-device estimate's lower confidence bound is 1.00, and the authors were cautious. Use practical limits without promising that avoiding screens guarantees no myopia. The Chinese guidance recommends two hours outdoors daily, and outdoor activity has randomized support; see entry 4. The same Chinese guidance recommends regular refractive screening at ages 1–3, 4–6, and from seven onward to monitor hyperopic reserve; see entry 12. A language-development meta-analysis of 42 studies and 18,905 children found longer screen time associated with weaker language skills, r=−0.14, 95% CI −0.18 to −0.10, but co-viewing and educational content with positive associations, r=0.16 and 0.13. These are associations, not proof of causation, and support avoiding screens as a substitute for conversation.
Research & references
General Office of the National Health Commission (2023). Ten Key Facts on Preventing and Controlling Myopia in Children and Adolescents, Guoweiban Fuyouhan [2023] No. 278. https://www.gov.cn/zhengce/zhengceku/202307/content_6894284.htm; Ministry of Education and seven other departments (2018). Implementation plan for comprehensive prevention and control of childhood and adolescent myopia, Jiaotiyi [2018] No. 3. http://www.moe.gov.cn/srcsite/A17/moe_943/s3285/201808/t20180830_346672.html; Foreman J, Salim AT, Praveen A et al. (2021). Association between digital smart device use and myopia: a systematic review and meta-analysis. The Lancet Digital Health, 3(12), e806–e818. https://doi.org/10.1016/S2589-7500(21)00135-7; Madigan S, McArthur BA, Anhorn C, Eirich R, Christakis DA (2020). Associations between screen use and child language skills: a systematic review and meta-analysis. JAMA Pediatrics, 174(7), 665–675. https://doi.org/10.1001/jamapediatrics.2020.0327