近视是青少年及婴幼儿中视力减退的常见病。它有遗传因素,也有后天环境的因素。绝大多数近视属于单纯性近视,其近视度数一般不超过3～4屈光度。近视的程度可有发展,但缓慢而轻微,到成人期,一般不再有明显的加深。当配戴适度的眼镜后视力均可完全矫正至正常。据调查,婴幼儿及青少年中近视的发生率随自然年龄的增长和学龄的升高而明显增加,中学生发生近视者比小学生高出2～4倍。这说明在后 Myopia is a common condition for vision loss in adolescents and infants. It has genetic factors, but also acquired environmental factors. The vast majority of myopia are simple myopia, the myopia is generally not more than 3 to 4 diopter. The degree of myopia may develop, but slowly and slightly, to adulthood, generally no significant deepening. When wearing moderate glasses, visual acuity can be completely corrected to normal. According to the survey, infants and adolescents in the incidence of myopia with the increase of natural age and school age increased significantly increased, high school students who have myopia than primary students 2 to 4 times. This is explained later