1. Sex: more women than men among students whose ratio of 1:0.8. The reason may be due to women's development of early, so women's short-sighted to stop earlier than that for males, but the prevalence of pathologic myopia was no difference between men and women.
2. Age: For acquired myopia increased with age, increasing myopia, simple myopic occurred in more than 10 years old.
3. Race: Han, large and national, Jewish, the Arab nation are more common; in China, the Han prevalence rate is highest, followed by Bai and so on, there are fewer Uygur, Kazak and so on.
4. Eye Do not: right eye left eye seems more common, are more severe in the left eye myopic.
5. Regional differences: the rural than urban.
6. Other: bad lighting; genetic; physique; systemic diseases; poisoning; eye other diseases.