Effect of Providing Free Glasses on Children - Educational Outcomes in China: Cluster Randomized Controlled Trial

  • The purpose of this study is to assess the effect of provision of free glasses on academic performance in rural Chinese children with myopia in 252 primary schools in two prefectures in western China.

  • Participants were 3177 of 19,934 children in fourth and fifth grades (mean age 10.5 years) with visual acuity <6/12 in either eye without glasses correctable to >6/12 with glasses. 3052 (96.0%) completed the study between 2012-2013.

  • Children were randomized by school (84 schools per arm) to one of three interventions at the beginning of the school year: prescription for glasses only (control group), vouchers for free glasses at a local facility, or free glasses provided in class.

  • Effect on test score was 0.11 SD when the free glasses group was compared with the control group.

  • The adjusted effect of providing free glasses was greater than parental education  or family wealth . This difference between groups was significant, but was smaller than the prespecified 0.20 SD difference that the study was powered to detect.

  • The provision of free glasses to Chinese children with myopia improves children’s performance on mathematics testing to a statistically significant degree, despite imperfect compliance, although the observed difference between groups was smaller than the study was originally designed to detect.

  • Myopia is common and rarely corrected in this setting.

Publication date

February 20, 2020




Ma X, Zhou Z, Yi H, Pang X, Shi Y, Chen Q, Meltzer ME, le Cessie S, He M, Rozelle S, Liu Y, Congdon N
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