After cataract surgery, the cataract usually does not recur, but there is a possibility of vision loss due to the development of posterior cataracts. The principle of cataract surgery is to remove the cloudy lens cortex and implant an artificial lens to replace the cloudy lens. The artificial lens is stable and will not change in character even if it is placed in the eye for a long period of time, so there is usually no recurrence after cataract surgery. During cataract surgery, a layer of the lens capsule will be retained as the space to carry the IOL, and some patients may experience cloudy lens capsule after surgery, resulting in posterior cataract that affects vision. The management of posterior cataract is relatively simple and can be cured by laser treatment. Younger patients are more likely to develop posterior cataracts than older patients, and cataract patients who experience vision abnormalities after surgery should seek prompt medical attention.