Myopia can be defined as a myopic refraction ≥ 50 degrees, which means that the minimum degree is 50 degrees and the maximum degree can be infinite. However, the maximum degree is generally between 3000-4000 degrees, and it is possible to see clinically that there may be 1-2 people with such a degree within thousands or tens of thousands of people. Such a person has a very high degree of myopia and can easily develop a pathology of the fundus, usually due to a high degree of family genetic predisposition to pathological myopia. Once a person has such a degree of myopia, it is important to check the fundus regularly, and if there is a problem with the fundus, it needs to be actively treated, also by posterior scleral reinforcement and crystal implantation, to try to reduce the degree of vision correction.