A cohort study was conducted in 96 primary and secondary schools in 16 districts of Tianjin from 2018 to 2020, including about 36452 people totally. The changes in myopia rate in 3 years were compared by a generalized estimation equation. The distribution of average equivalent spherical mirror and different regions and grades was evaluated by linear regression analysis, and the correlation between the equivalent spherical mirror and different gender, nationality, and age was evaluated.
This cohort study aimed to assess the change of refractive status in Chinese school children.