Some people who are not myopic may be related to a variety of factors, such as visual reserve, genetic factors, eye usage, and environmental influences. In daily life, patients should maintain good eye habits and do outdoor exercises regularly to help reduce the probability of myopia.1. Vision reserve: If a child is not myopic, the factor of vision reserve needs to be considered. In the early childhood stage, children’s eyes are in a state of hyperopia, which gradually returns to normal as they grow older. During this period, even if the child develops myopia, but because both eyes are farsighted, they only show “normal vision” compared to their peers; 2. Genetic factors: an important factor in the occurrence of myopia, from a medical point of view, myopia can be divided into simple myopia and pathological myopia. If both parents have high myopia, the probability of high myopia in children will be very high. If one parent is highly myopic and the other has normal vision, the probability of having a child with high myopia is about 50%. If both parents are not myopic, while paying attention to the acquired eye habits, the probability of myopia is reduced, so genetic factors have a great relationship with the occurrence of myopia; 3, eye use: reasonable control of the time to watch the video and the distance from the screen, watch the video try to choose a larger screen of electronic products. School-age children should control video time within one hour per day to reduce the probability of myopia; 4. Outdoor activities: If patients spend at least two hours a day outdoors in the sun, natural light can promote the release of dopamine from the retina, which can slow down the development of myopia. Therefore, in daily life, it is recommended that patients write and read in a well-lit environment, and take breaks in between to look into the distance as much as possible or do eye exercises, which can relax the ciliary muscle and slow down visual fatigue. It is also necessary to eat a balanced diet, not to be picky or partial, and to eat less sweets and sugary drinks to promote healthy vision.