ABSTRACT
PURPOSE: To determine the prevalence and risk factors of self-reported symptoms of Computer Vision Syndrome (CVS) in school students during COVID-19 pandemic. METHODS: In this cross-sectional study in Nanjing, China, students (grades 1-12) from six randomly selected schools self-administered the online survey questionnaire about hours on electronic devices, outdoor activities, frequency and intensity of 17 CVS symptoms during virtual learning period of COVID-19 pandemic. RESULTS: Among 2363 invited students, 2005 (84.8%) completed the survey. Mean (SD) age was 12 (3.0) years, 51% were male, 53% wore glasses, 56% did not know the 20-20-20 rule (take a 20 second break every 20 min of close work and gaze at objects at least 20 feet away) and 6.5% knew but never followed the 20-20-20 rule. Mean (SD) hours/day was 4.6 (3.4) for screen time and 1.2 (1.0) for outdoor activities. Total of 1543 (77.0%) students reported at least one CVS symptom (median = 4) with eye dryness and itching the most common (48%). In multivariable analysis, CVS score 4 or more was independently associated with older age (adjusted odds ratio (aOR) = 1.05 for per-year increase, p = 0.02), children with myopia not wearing glasses (aOR = 2.12, p = 0.0003), astigmatism (aOR = 1.37, p = 0.04), other ocular diseases (aOR = 1.59, p = 0.005), not complying 20-20-20 rule (aOR = 2.13, p = 0.04), more screen time (aOR = 1.53 for >6 vs. ≤2 hours, p = 0.0001) and less outdoor activities (aOR = 1.37 for ≤0.6 vs. ≥1.9 hours, p = 0.005). CONCLUSIONS: During COVID-19 pandemic, self-reported CVS symptoms occurred in more than three-quarters of students. Besides pre-existing ocular diseases, children with myopia not wearing glasses, excessive time on screens, non-compliance of the 20-20-20 rule and reduced outdoor activities were associated with higher risk of CVS.