Effects of behaviors and surrounding environment on myopia before and during the COVID-19 pandemic: a longitudinal analysis of children and adolescents in China

AIM: To investigate the relationship between related factors and visual acuity of Chinese school students before and during the COVID-19 pandemic. SUBJECT AND METHODS: Chinese students from primary and secondary schools were included from the Chinese National Surveys on Students’ Constitution and Health CNSSCH (2019). A total of 1496 participants completed follow-ups in June and December 2020, respectively. Generalized estimating equations were used to test the differences in visual environment. Logistic regression models were utilized to examine the roles of behaviors and surrounding environment changes associated with myopia before and during the pandemic. RESULTS: The prevalence of myopia was 47.7%, 55.6%, and 57.2% in baseline and two follow-ups, respectively. Significant differences existed for gender, learning level, and region (all P < 0.05). The proportion of new myopia and myopia torsion was the highest in the primary schools. Multivariate logistic regression analysis found that screen time ≥ 4h/d (OR = 2.717), poor eye habits (OR = 1.477), insufficient lighting for studying at night (OR = 1.779), desk or roof lamps only (OR = 1.388), and poor sleep quality (OR = 4.512) were the risk factors for myopia (all P < 0.05), and eye exercises (OR = 0.417), milk intake (OR = 0.758), and eggs intake (OR = 0.735) were the protective factors for myopia (all P < 0.05). CONCLUSION: Prevalence of myopia increased among Chinese students before and during the COVID-19. It is necessary to pay more attention to the pupils’ visual acuity, especially in primary school students, in the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10389-023-01900-w.