Ordinarily, cataract surgery is not urgent. Only in rare instances, when a cataract causes severe inflammation in the eye or glaucoma, does the cataract surgery become necessary as an emergency operation. There may also be instances where the development of the cataract makes it difficult for the doctor to view the back of the eye to treat other eye conditions. The doctor may then advise the patient to proceed with cataract surgery.  Modern surgical advances make cataract surgery very successful. Visual recovery is quick thanks to intraocular lens implants.