[Nature of myopia in young people].
D000293:Adolescent; D002648:Child; D002681:China; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008403:Mass Screening; D009216:Myopia / Q000145:classification / Q000453:epidemiology*; D012030:Refractive Errors