Prevalence of myopia in urban and rural children in mainland China.

It has been well recognized that myopia more likely affects East Asians, particularly the Japanese and Chinese population. Although some studies have reported the prevalence of myopia in children living in mainland China, most of these studies are based on subjects with unknown representativeness, non-uniform definition, and measurement methods. A higher prevalence of myopia in urban settings, compared with rural settings, has been consistently suggested in several studies. This article intends to review the available data on the prevalence of myopia in Chinese children living in China; particular consideration is given to the evidence of urban-rural differences and their implications.