The impact of vision care program on the mental health of migrant children in Eastern China: evidence from a cluster-randomized controlled trial

Background: Vision impairment is common among children and is known to affect learning, but its impact on children’s mental health has received less attention, especially in low- and middle-income countries. This study aims to focus on a school-based vision care intervention for migrant children in China to examine how the intervention affect children’s mental health. Methods: A randomized controlled trial was conducted to examine the causal impact of a vision care intervention on children’s mental health in 94 migrant schools. After baseline screening of 4,376 students, 682 children with visual impairments were assigned to either intervention or control groups. The intervention included distributing free eyeglasses, providing teacher incentives to encourage utilization, and offering informational education. Follow-up survey was conducted after six months. 309 children in the intervention group and 327 in the control group were included in the analysis. Intention-to-treat effects were estimated with standard errors clustered at the school level. Results: Overall, the intervention resulted in a significantly higher risk of mental health issues among migrant children, particularly learning anxiety. The adverse effects disproportionately impacted children whose teachers did not support wearing glasses, whose parents or peers did not wear glasses, and who had moderate or severe vision impairment. The lack of support from teachers hindered students from developing positive perceptions of glasses use and acquiring knowledge about vision care, which subsequently negatively influenced their mental health. Conclusion: Providing eyeglasses alone may not be sufficient to improve the well-being of migrant children. Without support from teachers, parents, and peers, vision care programs may lead to unintended increases in anxiety. School-based health programs should consider both physical and mental health needs and place greater emphasis on the social environment in which interventions are delivered.