5He M,Huang W,Zheng Y,et al. Refractive error and visual im-pairment in school children in rural southern China. [ J]. Oph-thalmology ,2007,114(2) :374 -382.
6Maul E, Barroso S, Munoz SR,et al. Refractive error study inchildren:results from La Florida,Chile[ J]. American Journal ofOphthalmology, 2000,129 (4) :445 -454.
7Murthy GVS,Gupta SK, Ellwein LB,et al. Refractive error inchildren in an urban population in New Delhi. [ J]. Invest Oph-thalmol Vis Sci,2002,43(3) :623 -631.
8Yi H,Zhang L,Ma X,et al. Poor vision among China’s ruralprimary school students : prevalence, correlates and consequences[J]. China Economic Review,2015(33) :247 -262.
9Congdon N,Wang Y, Song Y, et al. Visual disability, visualfunction,and myopia among rural Chinese secondary school chil-dren :the Xichang Pediatric Refractive Error Study (X-PRES) -re-port 1. [ J]. Investigative Ophthalmology and Visual Science,2008,49(7) :2888 -2894.
10He M, Zeng J,Liu Y, et al. Refractive error and visual impair-ment in urban children in southern China [J]. Investigative Oph-thalmology and Visual Science,2004,45(3) :793 -799.