Myopia Incidence and Lifestyle Changes Among School Children During the COVID-19 Pandemic: A Population-Based Prospective Study

  • The impacts of social restrictions for COVID-19 on children’s vision and lifestyle remain unknown. 

  • The study aims to investigate myopia incidence, spherical equivalent refraction (SER) and lifestyle changes among schoolchildren during the COVID-19 pandemic.

  • Two separate longitudinal cohorts of children aged 6–8 years in Hong Kong were included. The COVID-19 cohort was recruited at the beginning of the COVID-19 outbreak, whereas the pre-COVID-19 cohort was recruited before the COVID-19 pandemic. 

  • All children received ocular examinations, and answered a standardised questionnaire relating to their lifestyle, including time spent on outdoor activities and near work, both at baseline and at follow-up visits.

  • A total of 1793 subjects were recruited, of whom 709 children comprised the COVID-19 cohort with 7.89±2.30 months of follow-up, and 1084 children comprised the pre-COVID-19 cohort with 37.54±3.12 months of follow-up. The overall incidence was 19.44% in the COVID-19 cohort, and 36.57% in pre-COVID-19 cohort. 

  • During the COVID-19 pandemic, the change in SER and axial length was –0.50±0.51 D and 0.29±0.35mm, respectively; the time spent on outdoor activities decreased from 1.27±1.12 to 0.41±0.90 hours/ day (p<0.001), while screen time increased from 2.45±2.32 to 6.89±4.42 hours/day (p<0.001).

  • We showed a potential increase in myopia incidence, significant decrease in outdoor time and increase in screen time among schoolchildren in Hong Kong during the COVID-19 pandemic.

  • Our results serve to warn eye care professionals, and also policy makers, educators and parents, that collective efforts are needed to prevent childhood myopia—a potential public health crisis as a result of COVID-19.

Publication date

August 18, 2021


British Journal of Ophthalmology

Sponsor Institution

This study was supported in part by CUHK Jockey Club Children Eye Care Programme, the General Research Fund (GRF), Research Grants Council; the Collaborative Research Fund (CRF), Research Grants Council; Innovation and Technology Fund (ITF), Innovation and Technology Commission; Health and Medical Research Fund (HMRF), and the direct grants of the Chinese University of Hong Kong; the UBS Optimus Foundation Grant 8984 (JCSY); and the Centaline Myopia Fund (JCSY).


Zhang X, Cheung SSL, Chan H, et al
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