A Better Vision for Development: Eyeglasses and Academic Performance in Rural Primary Schools in China

About 10% of primary school students in developing countries have poor vision, but very few of them wear glasses. Almost no research examines the impact of poor vision on school performance, and simple OLS estimates are likely to be biased because studying harder often adversely affects one’s vision. This paper presents results from a randomized trial in Western China that offered free eyeglasses to rural primary school students. The most conservative of our preferred estimates, which averages across data from two counties, indicates that wearing eyeglasses for one academic year increased average test scores of students with poor vision by 0.16 standard deviations, equivalent to 0.3 additional years of schooling, but the preferred estimate that is based on the one county where data collection was more closely monitored suggests that wearing eyeglasses increased test scores by 0.41 or more standard deviations, equivalent to 0.9 additional years of schooling. We also find that the benefits are greater for under-performing students. A simple cost-benefit analysis suggests very high economic returns to wearing eyeglasses, raising the question of why such investments are not made by most families. We find that girls are more likely to refuse free eyeglasses, and that lack of parental awareness of vision problems, mothers’ education, and economic factors (expenditures per capita and price) significantly affect whether children wear eyeglasses in the absence of the intervention. Data collection for the Gansu Survey of Children and Families was supported by grants from The Spencer Foundation Small and Major Grants Programs (wave 1), by NIH Grants 1R01TW005930-01 and 5R01TW005930-02 (wave 2), and by a grant from the World Bank (wave 2). Travel was supported by the Center for International Food and Agricultural Policy at the University of Minnesota.