Abstract: Objective To investigate the prevalence of myopia among 3~6 year old preschool children in Haidian District, Beijing and analyze its influencing factors. Design Cross-sectional study. Participants 1864 preschool children from 27 kindergartens in Haidian District, Beijing. Methods The visual acuity and diopter of the children were tested using LogMAR visual acuity chart and computer optometer which test after cycloplegia with 1.0% cyclopentate hydrochloride. Daily outdoor activity time, daily use time of electronic products, daily total sleep time, reading and writing posture, picky eating, and abnormal eye performance and parents' myopia were collected by questionnaire. Myopia is defined as equivalent spherical ≤-0.50 D. Multivariate logistic regression analysis was used to analyze the influencing factors of myopia.  Main Outcome Measures myopia prevalence, risk factors. Results The prevalence of myopia was 4.61% in the 1864 preschoolers, in which, 5.35% in boys and 3.81% in girls (P＞0.05). Multivariate analysis showed that at least one parent myopia (OR=1.60, P＜0.05), daily outdoor activity time <2 hours (OR=0.03, P＜0.05), daily use of electronic products(OR=1.07, P＜0.05), daily sleep time less than 10 hours (OR=1.89, P＜0.05) and abnormal eye appearance (OR=1.34, P＜0.01) were positively correlated with the prevalence of myopia. Conclusion The prevalence of myopia among preschool children in Beijing Haidian District is about 4.6%. Appropriately increasing outdoor activity time, ensuring sufficient sleep, controlling the use of electronic devices, showing abnormal eye symptoms, and paying more attention to children whose parents have a history of myopia can help prevent and control myopia in preschool children. (Ophthalmol CHN, 2024, 33: 362-366)

Key words: myopia, preschool children, epidemiology