During the normal development of the eye, the development of the various “parts” of the eye must be coordinated and balanced with each other, and if they are well matched, our eye will develop into an ortho-optic eye, which is the process of orthokeratology. If any one of these “components” is abnormal and the other “components” cannot compensate effectively, refractive error (myopia, hyperopia, astigmatism) will occur. Current research confirms that the interaction of genetic and environmental factors is an important cause of myopia. The occurrence and development of myopia is closely related to the individual’s physical condition. Current research and statistics show that if one parent has high myopia, the offspring will have an epiphenomenon rate of 50%, and if both parents are highly myopic, the offspring will have an epiphenomenon rate of 80%. Early and excessive near eye use, such as improper posture in writing, long reading time, playing with cell phones, computers, game consoles, practicing piano, playing with small toys, etc., cause excessive near-visual load and are the main environmental factors that induce myopia. Conclusion of myopia etiology The best conclusion of myopia etiology is that the poor eye environment increases the ectopia and expressivity of myopia genes during the period when the child’s eyes are developing fastest and most unstable, and therefore, eventually leads to the occurrence of myopia. Excessive eye use at close range is the catalyst for the myopia gene. People with myopia genetic makeup are more significantly affected by poor eye use habits. Not only does the onset of myopia occur at an early age, but myopia progresses more quickly and the chances of developing high myopia are greatly increased. Prevention and control of myopia Prevention of myopia should start at an early age, children should develop good eye habits after birth, do not read books, play with cell phones and computers too much, and go to regular, professional eye clinics or eye hospitals for health checks after the age of 3. The most important thing to remember is that myopia is the most rapid period of physical development, and it is also the period when children go to school and use more eyes, which is a high-risk period for myopia. The most important thing to do is to look less near and more far; to participate in daytime outdoor activities; to have balanced nutrition, to consume less sweets and beverages, and to try to make your child’s myopia occur later, to deepen myopia more slowly, and to avoid negative consequences in the future.