A posterior cataract is a clouding of the posterior capsule of the lens. It is different from a cataract in the traditional sense because the treatment of a posterior cataract requires a laser to cut open the posterior capsule. The timing of treatment for posterior cataract is as early as possible. Once a posterior cataract is detected and it is obvious that it is affecting vision, laser dissection can be performed. Posterior cataracts will occur 6 months after surgery, usually a little later in some people, around 3-4 years, and in some people it may be 7-8 years after surgery before the posterior cataract occurs. However, this can happen to almost everyone. Once the posterior cataract occurs, do not be too anxious, just after the doctor’s examination, the YAG laser treatment can cure the posterior cataract and improve the vision up.