The Associations between Near Visual Activity and Incident Myopia in Children: A Nationwide 4-Year Follow-up Study

  • The study aimed to examine the prospective association between near visual activities and incident myopia in Taiwanese children 7 to 12 years old over a 4-year follow-up period.

  • There were 1958 children aged 7 to 12 years from the Taiwan 2009 National Health Interview Survey who were linked to the 2009 through 2013 claims data from the National Health Insurance system.

  • The study estimated the associations between 3 types of near visual activities in sedentary posture, namely reading (< 0.5, 0.5-0.9, ≥1.0 hours per day [h/d]), use of computer, Internet, and games (<0.5, 0.5-0.9, ≥1.0 h/d), and “cram school” attendance (<0.5, 0.5-1.9, ≥2.0 h/d), and incident myopia.

  • Overall, 26.8% of children had myopia at baseline, and 27.7% of those without myopia at baseline developed incident myopia between 2010 and 2013. 

  • On average, they spent 0.68±0.86 h/d on computer/Internet use, 0.63±0.67 h/d on reading, and 2.78±3.53 h/d on cram school. 

  • The results showed that children attending cram schools ≥2 h/d (hazard ratio, 1.31; 95% confidence interval, 1.03-1.68) had a higher risk of incident myopia. The effects of these activities remained similar in sensitivity analyses.

  • The study concluded that cram school attendance for ≥2 h/d may increase the risk of children’s incident myopia. This effect may be due to increased near visual activity or reduced time outdoors.

Publication date

July 7, 2021




Po-Wen Ku, Andrew Steptoe, Yun-Ju Lai, Hsiao-Yun Hu, Dachen Chu, Yung-Feng Yen, Yung Liao, Li-Jung Chen
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