Is myopia hereditary? This is a question that is of great concern to many parents. Nowadays, vision is required for school, military, and job hunting, and every parent wants their children to have clear and bright eyes, regardless of whether they are nearsighted or not. But in fact, it is safe to say that myopia is hereditary. According to group surveys, it has long been proven that the incidence of myopia varies greatly among ethnic groups, with myopia occurring more often among Asians with the Chinese and Japanese, and more often among Jews in Europe than among natives of England, Germany and other countries. This indicates that the occurrence of myopia is related to ethnicity and race. 60 years ago, foreign scholars reported that twins not only have myopia and astigmatism in both eyes, but also have exactly the same number of degrees; ophthalmologists in China have also studied twins and found that the refractive power of both eyes of twins is very close, especially the correlation between identical twins is higher. This suggests that genetic factors play an important role in the development of myopia. Since myopia is hereditary, why are some children myopic when neither parent has myopic eyes? Some parents with high myopia are also very concerned about whether their children will definitely have high myopia in the future. In fact, myopia inheritance is not a simple issue, there is a lot to learn! Myopia can be divided into simple myopia and pathological myopia, and the two types of myopia are inherited in different ways. The prevalence of simple myopia, also known as school myopia or acquired myopia, is about 25-30% in the population, mostly after the onset of high school, and the degree is basically stable after the development of adolescence, generally not more than 1000 degrees, the length of the eye does not exceed 28 mm, corrected visual acuity can be more than 1.0, belongs to polygenic inheritance, influenced by the environment, the role of environmental factors than genetic factors. The most common type of myopia among adolescents is simple myopia, the onset of which is mostly related to long-term reading and writing and other close work after school. Genetic factors have a limited role in myopia, being only a biological prerequisite in the process of myopia occurrence and development, providing only the possibility of myopia, while environmental conditions determine the reality of myopia occurrence and are formed through the action of genetic qualities. Because of this, the occurrence of myopia in children does not look very relevant to the presence or absence of myopic parents. If both parents are simply myopic, myopia can be avoided or reduced if the child pays attention to eye hygiene and takes a break after reading or writing for a period of time, while if both parents are not myopic, myopia can easily occur when the child is over-adjusted due to prolonged eye strain. Pathological myopia, also known as congenital myopia, has a prevalence of 1 to 2% in the population, and the age of onset is mostly before primary school, with myopia increasing with age and eventually exceeding 1000 degrees, with an eye length of more than 28 mm and corrected visual acuity of less than 1.0, and prone to serious complications such as macular hemorrhage, degeneration and even retinal detachment. Scientific studies have shown that this myopia is an autosomal recessive disease, which is mainly controlled by genetic factors, with environmental factors playing a very small role. Specifically, each parent has a pair of alleles that control the development of pathological myopia and each passes one of them to the next generation. If the child gets two genes that are normal, he is a pure normal person; if he gets one normal gene and the other is pathogenic, he is a normal carrier; if he gets two genes that are pathogenic, he is a pathological myopia The patient. Therefore, if both parents are pathologically myopic, the resulting child will also be pathologically myopic; if one parent is pathologically myopic and the other is a carrier, half of the resulting children may be patients and half may be carriers; if both parents are carriers, 1/4 of their children may be normal, 1/4 may be patients, and 1/2 may be carriers; if one parent is a patient and If one parent is a pure normal, all children are carriers. This mode of inheritance is independent of sex. Of course, the problem is not so simple, the above is just a pattern, the real process of inheritance will be influenced by factors such as epiphenomenon, scientists are doing further research. Myopia is hereditary, but it does not mean that children can not protect their eyes, because after all, the environment also plays a big role in the occurrence of myopia. It is important to pay attention to eye hygiene and do the “three things” and “three don’ts” to prevent and reduce the occurrence and development of myopia. Children with pathological myopia in their families are more likely to develop myopia than the general population, but with early detection and treatment, the development of myopia can still be slowed.