Four major causes of myopia in children

Myopia is a common eye disease, which is mostly caused by teenagers who use their eyes at close range for a long time. Teenagers are under great study pressure. Reading or watching TV for a long time will cause excessive eye fatigue. If they do not pay attention to eye rest and eye hygiene, it is easy to induce myopia. The common causes of myopia in adolescents are as follows:

1. Using your eyes too close

Most adolescent myopia is caused by long-term use of the eyes at too close a distance. The eyes of teenagers have a strong ability to accommodate objects. They can still see objects clearly when the distance between the book and the eyes is 7-10 cm. However, if they often read or write at this distance, the eye's accommodation will become abnormally tense, which can lead to refractive (accommodative) myopia, the so-called pseudomyopia. If the eye is over-adjusted for a long time, the ciliary muscle cannot stretch and contract flexibly. The convergence effect is enhanced due to the over-adjustment, which causes the extraocular muscles to exert pressure on the eyeball, increasing the intraocular pressure and causing congestion of the intraocular tissue. In addition, the eyeball tissue of teenagers is delicate, and the eyeball wall is gradually stretched under pressure, causing the anterior-posterior axis of the eyeball to lengthen. When it exceeds the normal value, axial myopia is formed, the so-called true myopia. The normal reading distance should be 30-35 cm.

2. Using your eyes for too long

Some teenagers read books, write, do homework, watch TV, etc. for 3-4 hours without rest, and even go to bed and rest late at night. This not only affects physical health, but also puts too much burden on the eyes, causing the muscles inside and outside the eyes to grow.

The time is in a tense state without rest. Over time, when looking into the distance, the eye muscles cannot relax and are in a spasmodic state, so that distant objects appear blurred and myopia is formed. Some students' eyesight improved after a summer vacation.

This is the reason for the apparent decline. It is generally recommended that you take a short break or look into the distance after reading, writing or watching TV for 40-50 minutes.

3. The lighting is too strong or too weak

If the light is too strong, such as sunlight shining on written material, it will cause strong reflection, irritate the eyes, make the eyes uncomfortable, and make it difficult to see the font clearly. On the contrary, if the light is too weak and the written material is insufficiently illuminated, the eyes cannot see the font clearly, and the head will move forward and get close to the book. Both of the above situations can easily cause eye fatigue, excessive adjustment or spasm of the eyes, and form myopia.

4. Reading in the car or while walking

Some young people make full use of their time by reading while walking or in a moving car, which is very bad for their eyes. Because the car is vibrating and the body is swaying, the distance between the eyes and the book cannot be fixed. In addition, the lighting conditions are poor, which increases the burden on the eyes. If this happens frequently, it may cause myopia.