Myopia in children is one of the most serious social public health problems and the biggest nuisance for the healthy development of the majority of our youth. In recent years, the prevalence of myopia among children has remained high, and there is a trend of continuous increase. How to prevent and control myopia is the most important topic for parents and one of the top five urgent issues of Vision 2020 in China. Many studies have shown that the earlier the age of myopia, the more likely it is to lead to high myopia, which is a high risk factor for blindness such as retinal detachment, open-angle glaucoma, and early-onset cataracts. According to the World Health Organization (WHO) recommendations, increasing children’s time outdoors is currently the only recognized and effective way to prevent myopia. Scientists have found that the incidence of myopia is low in other non-human primates, and that reducing the amount of time primates spend exposed to sunlight during infancy can easily induce the onset of myopia. People receive more than 100 times the intensity of sunlight outdoors than indoors. For children, at least 14 hours of outdoor activity per week should be guaranteed, which is 2 hours of outdoor activity per day. One study reported that increasing outdoor activity by one hour per week can reduce the incidence of myopia by 2 percent. Parents, please note that this must be outdoor exercise, not indoor rest as we often say. Why does increasing outdoor activity time control myopia development? It is generally believed that it may be mainly due to the following factors: (1) sunlight increases vitamin D production; (2) outdoor sunlight exposure promotes the release of more chemicals such as dopamine from the retina; and (3) outdoor activities allow children to increase more visual distance and more exposure to beneficial microorganisms. Corneal shaping lenses are also one of the more widely used methods of controlling myopia in recent years. There has been some controversy about keratoplasty lenses in China, and questions have been raised about their safety. But nearly 20 years of development have shown us that keratoplasty is a very safe and effective means of controlling myopia. If outdoor activities focus on prevention, keratoplasty focuses on control. I will cover the application of keratoplasty lenses in more detail in other articles. Parents need to be aware that they must go to a regular hospital for fitting, and do a good job of cleaning and care and regular review. The third is the use of a low concentration of dilating medication (such as atropine) to dilate the pupil and achieve relief of the ciliary muscle, thus controlling and preventing myopia, which is very effective in the early stages of myopia. This method is also widely used around the world, but its specific effects still need further verification by everyone. As for various other popular massagers, acupuncture, etc. on the market, they are one of the characteristics of our country. I would like to say that for these I really do not understand, indeed there are many children after massage can be very good control of myopia, very amazing, but its specific mechanism is unclear. Parents who are interested can try it, but we do not recommend it. In short, so far there is no definite way to prevent and control the occurrence and development of myopia with zero damage, except for outdoor sports. Increasing outdoor exercise is the only way to control and prevent myopia!