After laser surgery, myopia appears again according to the time, the specific reasons are as follows: 1, if the situation is early, such as just 3 days or 0.5-1 months after the myopia, often the surgery is done under correction, not enough degrees, but also can be related to the state of the machine, the degree of cooperation, eye absorption capacity of the laser; 2, if the late, such as six months later and myopia, we should refer to the pre-operative Refractive state; most highly myopic patients after surgery, easy to refractive regression, regression rate is generally about 10%, so most of these patients because the body remodeling, or corneal repair caused. This kind of patients generally need to be observed for six months, if six months appear, to be observed for another 3 months, another 3 months, to see its also become unchanged, and then do further treatment. 3, refractive surgery has been carried out for more than 20 years, such as surgery done 20 years ago, and now began myopia, these are often late in the use of cell phones, computers, and the emergence of new myopia. These patients also need to be observed to see if they are stable and then post-treatment is done.