根据世界卫生组织对视力损害进行的分类定级,最佳矫正视力在0.05以下至无光感者为盲;最佳矫正视力在0.3～0.05者为低视力。低视力与盲之比约为3∶1。据统计我国的双盲率约在0.4‰,按此比例,我国的低视力患者人数是相当大的。低视力及盲可给个人和社会造成很大的负担,同时低视力与盲密切相关,低视力可以发展成盲。但低视力既不同于盲,又不 According to WHO classification of the classification of visual impairment, the best corrected visual acuity in 0.05 or less to blind feeling blind; best corrected visual acuity in 0.3 ~ 0.05 were low vision. The ratio of low vision to blindness is about 3: 1. According to statistics, the double blind rate in our country is about 0.4 ‰. According to this ratio, the number of low vision patients in our country is quite large. Low vision and blindness can be a heavy burden on individuals and society, while low vision is closely linked to blindness and low vision can develop into blindness. However, low vision is different from blindness, not