It is now generally accepted that there are two major factors that cause myopia, firstly, genetic factors and secondly, environmental factors. And environmental factors are the main cause of myopia. The occurrence of myopia is related to heredity, especially in highly myopic eyes. People who have two or one parent with myopia are significantly more likely to develop myopia compared to the normal population. The prevalence of myopia in children and adolescents is increasing, and the age of onset is getting earlier. The main reason is that they are still too “nerdy”, such as early exposure to electronic products, attending various study classes on weekends, staying in air-conditioned rooms all day, and lacking necessary outdoor sports. Because of prolonged close eye use, the ciliary muscles tend to be in a state of spasm all the time, which is manifested as reduced distance vision, and if not rested in time, it may gradually lead to true myopia and further elongation of the eye axis. If you often participate in outdoor sports, your eyes often look far, the ciliary muscle can get sufficient rest, while ultraviolet radiation to the eyes, can stimulate the body to produce dopamine, can strengthen the toughness of the eye, to prevent the elongation of the eye axis, can effectively prevent the development of myopia. Because myopia is irreversible, it is necessary to actively prevent the occurrence of myopia. If abnormalities are found, you need to go to a regular hospital ophthalmology department to receive treatment in a timely manner.