... accounting for 71% of the area in main-land China), and includes eleven provinces and one municipality, but the population is relatively sparse (360 million, accounting for only 28% of ... in these areas are different from the results of epidemiological studies from China [8, 9, 10] and the prevalence of myopia is higher in China, indicating that differences in ethnicity, ... vision and refractions in Western China. In order to obtain the refractive status in school-age children in Western China, we selected Yongchuan District, Chongqing, a representative...