A 12-year-old child who develops myopia must pay attention to it, because under normal circumstances, the development of myopia can not be completely stopped until about 18 years old, and until then, there is almost an annual increase of about 50-100 degrees. Therefore, if a child starts to develop myopia from the age of 12, the possibility of high myopia is still relatively high when the child is 18 years old. Therefore, once myopia appears, the first thing to do is to take your child to the hospital for an optometric examination to clarify the degree of myopia and to wear glasses early, only then can you slow down the development of myopia. In addition, in life, we should pay attention to let children maintain a reasonable eye habits, try to avoid bad eye habits, such as close use of computers, cell phones and other electronic products for too long. It is necessary to increase the time spent outdoors in daily life, so that the speed of myopia development can be controlled.