You can see big portion of middle school and college students even pupils wear glasses in classes or outdoors, most of these glasses they wear are eye glasses, I think the main reason for this situation is that many student are lay on burdensome studying, especially for those high school and college students, their studying task is heaviest, they must study from morning to night, and their eyes keep focusing on the book all the time, it is easy to become near-sighted if they develop bad habits; and the radiation of computer also harmful to our eyes, so those students who like surfing on line are become myopic easier. Near-sighted is inconvenient in studying and working, without the glasses their visual is vague and they will live in dim world. Those students who have pass college entrance exam even meet difficulty in choosing their major before enter into colleges, because some universities don’t accept near-sighted students.