Theoretically, as long as myopia is detected through medical optometry, even if it is only 25 degrees or even lower, it is still myopia, but in clinical practice, myopia of 75 degrees or more needs to be treated, that is, myopia with clinical significance. The prevalence of myopia in China is the highest in the world, and the development of myopia has a tendency to become younger and more serious. The eyes of children and adolescents are still immature and the eye axis is always growing, so if they suffer from myopia too early, myopia will inevitably increase. If children are diagnosed with myopia, it is important to establish a visual health file, review their vision once every six months, and update the contents of the file with a yearly optometry. Make sure to spend at least one hour outdoors every day, soak in the sunshine, reduce the burden of close eye use as much as possible, look far away for a long time, look at green plants, which is very good for eye fatigue relief, ensure balanced nutrition, eat less sweets, drink less carbonated drinks, and ensure sufficient sleep time every day.