Myopia is caused by a combination of congenital and acquired factors. Many people believe that congenital factors are genetic in nature, but this is not comprehensive. Numerous studies have found that myopia, especially high myopia, that is, myopia of 600 degrees or more, has a certain genetic predisposition, but it is not always inherited. However, it is not always inherited because some parents are not highly myopic, or one or both parents are not myopic, and their children may be myopic. Some parents have a high myopia level of 700 or 800 degrees or even more than 1000 degrees, and their children may not develop myopia. There is no definitive answer to the question of how much myopia is inherited and how many degrees of myopia are inherited. However, some studies have found that people with higher myopia and longer eye axes have a higher risk of myopia in their children. It is difficult to study the heritability of myopia because, in addition to congenital factors, acquired factors are also important in the development of myopia. Therefore, the generally accepted view is that high myopia has a higher risk of heritability, but it is not necessarily inherited.