Based on the common means of myopia prevention and control in the market and relying on literature research, this paper compares the defocus theory and its application in myopia prevention and control, and finds that the functional lens with asymmetric peripheral defocus design is effective for myopia control of children and adolescents and can achieve a balance of visual comfort. At the same time, accurate matching of the defocus amount can better meet the needs of different groups of people. But in actual clinical applications, it is necessary to choose suitable products for customers, so as to achieve the best control effect.