How do I know when I need cataract surgery?

Cataracts are considered a blinding disease, because, if they are not surgically removed, they will eventually lead to very poor vision. The key word here is “eventually,” because many people live their whole lives without undergoing cataract surgery. The way I think of it is that their other medical problems were worse than their cataract. However, there are certainly people in the world (more often outside the United States than in the United States) who are alive with terrible cataracts that completely prevent them from having useful vision. Most often, people in the United States have cataract surgery long before they get to very poor levels of vision. This is a good thing, so that people don’t have to suffer poor vision and because the cataracts are usually more easily removed before they are dense enough to cause that poor vision. So, the answer to the titular question is one that patients don’t often like; cataracts are ready to remove when patients have vision problems that are not correctable with glasses. Of course, the patient’s doctor has to find some cataract on exam, but there are may patients I have seen who are doing fine despite “grade 3 cataracts” and others who aren’t happy until their “grade 2 cataracts” are removed. One rule of thumb that I tell my family members is that people who have some vision complaints while wearing a good glasses prescription and are over 80 years old should have cataract surgery. But plenty of people have cataract surgery long before then.