*Article* **Student Health Implications of School Closures during the COVID-19 Pandemic: New Evidence on the Association of e-Learning, Outdoor Exercise, and Myopia**

**Ji Liu 1, Baihuiyu Li 1, Qiaoyi Chen 2,\* and Jingxia Dang 3,\***


<sup>3</sup> The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China

**\*** Correspondence: qychen203@xjtu.edu.cn (Q.C.); jxdang2000@126.com (J.D.)

**Abstract:** The coronavirus disease 2019 (COVID-19) pandemic forced many education systems to consider alternative remote e-learning modalities, which have consequential behavioral and health implications for youth. In particular, increased e-learning engagement with digital screens and reduction in outdoor activities are two likely channels posing adverse risks for myopia development. This study investigated the association between e-learning screen use, outdoor activity, lighting condition, and myopia development among school-age children in China, during the first wave of the COVID-19 pandemic. Data were collected from 3405 school-age children attending primary, lower-secondary, and upper-secondary schools in China. Univariate parametric and nonparametric tests, and multivariate logistic regression analysis were used. Findings show that each diopter hour increase in daily e-learning screen use is significantly associated with progression of myopia symptoms (OR: 1.074, 95% CI: 1.058–1.089; *p* < 0.001), whereas engaging in outdoor exercise four to six times per week (OR: 0.745, 95% CI: 0.568–0.977; *p* = 0.034) and one to three times per week (OR: 0.829, 95% CI: 0.686–0.991; *p* = 0.048) is associated with a lower likelihood of myopia progression than none at all. In addition, we found that indoor lighting that is either "too dim" (OR: 1.686, 95% CI: 1.226–2.319; *p* = 0.001) or "too bright" (OR: 1.529, 95% CI: 1.007–2.366; *p* = 0.036) is significantly associated higher likelihood of myopic symptoms. Findings in this study uncover the less observable vision consequences of the COVID-19 pandemic on youths through digital online learning and highlight the importance of considering appropriate mitigation strategies to deal with this emerging public health challenge.

**Keywords:** e-learning; youth and children health; visual health; myopia; COVID-19
