If children with common vision problems receive and use eyeglasses, their educational performance rises. Without proper treatment, visually impaired children may not achieve educational gains and could suffer from poor mental health. We use a randomized controlled trial to study the impact of an eyeglasses promotion program in rural China on the mental health of myopic primary school students. Three measures of mental health are used: learning anxiety, physical anxiety, and scores on the Mental Health Test (MHT). Our empirical analysis showed that on average, the treatment has small and insignificant for learning anxiety and MHT, and a small but significant reduction in physical anxiety. However, subgroup analysis reveals that myopic students who study more intensively see their learning anxiety and physical anxiety reduced after being provided with eyeglasses. In contrast, students with the lower study intensity suffer a rise in learning anxiety after receiving eyeglasses. A potential mechanism for the differing impacts is the increase in teasing reported among low study-intensity students that does not occur for high study-intensity students. Care should be taken to maximize the benefits and minimize the costs of in-school vision programs.