Table_1_Contribution of Total Screen/Online-Course Time to Asthenopia in Children During COVID-19 Pandemic via Influencing Psychological Stress.DOCX

Objectives: During the coronavirus disease 2019 (COVID-19) self-quarantine period, the transition to online-course has profoundly changed the learning modes of millions of school-aged children and put them at an increased risk of asthenopia. Therefore, we aimed to determine associations of the total screen/online-course time with asthenopia prevalence among that children during the COVID-19 pandemic, and whether the associations were mediated by psychological stress.
Methods: Asthenopia was defined according to a validated computer vision syndrome questionnaire (CVS-Q). We used CVS-Q to collect the frequency and intensity of 16 asthenopia-related eye symptoms of 25,781 children. Demographic features, eye care habits, visual disorders, lifestyle, psychological and environmental factors, were also collected.
Results: The overall asthenopia prevalence was 12.1%, varying from 5.4 to 18.2% across grade/gender-classified subgroups. A 100-h increment of total screen/online-course time were associated with an increased risk of asthenopia by 9% [odds ratio (OR) = 1.09] and 11% (OR = 1.11), respectively. Mediation analysis showed that the proportions of total effects mediated by psychological stress were 23.5 and 38.1%, respectively. Age, female gender, having myopia or astigmatism, bad habits when watching screens were also risk factors. Conversely, keeping 34–65 cm between eyes and screen, increased rest time between classes, and increased eye exercise were all associated with a decreased risk.
Conclusion: Our study indicated that the influence of long total screen or online-course time on psychological stress increases asthenopia risk. The findings of this study have provided a new avenue for intervening screen-related asthenopia in addition to incorporating a reasonable schedule of online courses into educational policy.

研究目的：在2019冠状病毒病（coronavirus disease 2019, COVID-19）疫情自我隔离阶段，在线课程的全面转型深刻改变了数百万学龄儿童的学习模式，也使其视疲劳风险显著升高。为此，本研究旨在探究新冠疫情期间儿童总屏幕/在线课程时长与视疲劳患病率的关联，并明确该关联是否由心理应激介导。
研究方法：视疲劳的判定采用经过验证的计算机视觉综合征问卷（computer vision syndrome questionnaire, CVS-Q）。本研究通过该问卷收集了25781名儿童的16种视疲劳相关眼部症状的发生频率与严重程度，同时采集了人口学特征、护眼习惯、眼部疾患、生活方式、心理及环境因素等相关数据。
研究结果：整体视疲劳患病率为12.1%，按年级与性别划分的亚组患病率在5.4%至18.2%区间内波动。总屏幕/在线课程时长每增加100小时，视疲劳风险分别升高9%[比值比（odds ratio, OR）=1.09]与11%（OR=1.11）。中介分析显示，心理应激介导的总效应占比分别为23.5%与38.1%。年龄、女性性别、合并近视或散光、不良屏幕观看习惯均为视疲劳的危险因素。反之，保持眼与屏幕间距34~65cm、增加课间休息时长与增加眼部锻炼，均与视疲劳风险降低显著相关。
研究结论：本研究证实，较长的总屏幕或在线课程时长可通过影响心理应激进而升高视疲劳风险。本研究结果为屏幕相关性视疲劳的干预提供了新方向，除了将合理的在线课程安排纳入教育政策之外。