Cataract surgery is a very routine surgery in ophthalmology. Although the surgery is very short, it is still an internal eye surgery, which is a very delicate surgery. Common complications after surgery mainly include: first, postoperative infection, which is relatively rare, but when it occurs, it can have a very obvious impact on vision. Second, intraoperative hemorrhage, also called subchoroidal hemorrhage, which is also very serious. Third, post-operative IOL dislocation, which refers to the situation where the IOL becomes skewed due to trauma after surgery. Fourth, post-operative cataract refers to the case where the eyes recover well after surgery, but after a period of time, such as six months, a year or longer, the vision decreases again and the posterior capsule is found to be cloudy after examination.