Attending a Sports Club Can Help Prevent Visual Impairment Caused by Cram School in Elementary School Children in Japan.

Longer durations for near-work activities, such as studying, worsen eyesight. In contrast, outdoor exercise is effective in reducing the risk of developing myopia. Despite these findings, however, the interaction between studying and exercise in eyesight has not been quantitatively evaluated. Moreover, since there is a culture of attending lessons in Japan, it is important to investigate the relationship between elementary school activities, such as cram schools or sports clubs, and vision. Therefore, in this study, we examined whether attending cram schools and/or sports clubs is associated with the use of glasses among elementary school students. We conducted a survey among 7419 elementary school students in Tokyo, Japan using a food education questionnaire. A logistic regression analysis was used to evaluate the relationship between wearing glasses, an objective variable, and attending sports clubs and cram schools. Sex and school year were considered confounding factors. The results of this study showed that students who attended only sports clubs were more likely to be categorized into the "not wearing glasses" group ( = 0.03, OR = 1.45), whereas those who attended only cram schools were more likely to be categorized into the "wearing glasses" group ( = 0.008, OR = 0.67). In addition, students who attended both cram schools and sports clubs were more likely to be categorized into the "not wearing glasses" group than those who only attended cram schools ( = 0.28, OR = 0.85). Our findings indicate that attending not only cram schools but also sports clubs may prevent deterioration of eyesight. Parents and health care providers need to take these findings into account in order to prevent visual impairment in children.