Each surgery can have complication but the doctor will minimize the risk. For cataract surgery, you may have detached retinal, glaucoma and eye infection after surgery. But the chance is rare and even if it happens, it can be successfully treated.
Even if the surgery has been performed successfully, certain complications may occur, e.g. glaucoma and intraocular pressure buildup. Other rare conditions include de-centered IOL, tearing of the posterior capsule and potentially detached retina. Some doctors think that detached retina has no direct relation to cataract surgery, since some patients have already suffered from this condition before the surgery. The most severe complication should be endophthalmitis, which causes widespread inflammation or infection. Fortunately, the rate of developing endophthalmitis is as low as 0.1%.
You may get eye inflammation after cataract surgery. If you get infection or bleeding inside the eye after cataract surgery, you may suffer severe vision loss. However, it is rare to suffer vision loss after cataract surgery and there is no need to worry about it.