Objectives: To describe the prevalence and causes of visual impairment in a representative sample of 3 to 6-year-old from Yuhua District, Nanjing, China.

Methods: Five thousand eight hundred eligible children in 29 kindergartens were identified. Participants’ parents were asked to complete a comprehensive 117-item questionnaire and were scheduled for a comprehensive eye examination in kindergartens and then in-clinic interview, if necessary. Visual acuity (VA) was measured in both eyes with spectacles if worn. Cycloplegic refraction and fundus examination were performed if necessary.

Results: Presenting visual impairment was found in 237 children. Uncorrected visual impairment was found in 254 children. 210 children (3.62%) had correctable visual impairment, caused by refractive error. 44 children (0.76%) had uncorrectable visual impairment. Refractive error was the most frequent cause, accounting for 210 children, followed by amblyopia. 166 children had pure astigmatism and 18 children had combined. 39 children were caused by amblyopia, 1 child caused by bilateral macular degeneration, 1 child caused by nystagmus, and 4 children caused by high myopia (contained 1 child with one eye caused by amblyopia, the other eye caused by amblyopia).