That depends on the type of cataract surgery you have. Medicare onlyl cover cataract surgery which is medically necesary. It only provide the coverage for the standard monofocal IOL during cataract surgery but not for a presbyopia-correcting IOL. Because the standard monofocal IOL is needed when the natural lens in your eye need to be removed and replaced with an artificial lens to restore your sight during cataract surgery. While a presbyopia-correcting IOL will allow you not to wear glasses after the surgery, which is not considered medically necessary.
Usually, medicare insurance will cover the cost for some eye care of some eye disease like cataract surgery. You shall talk with your Medicare representative before having cataract surgery so as to understand exactly how much is covered and how much you need pay for yourself. Of course, you shall make sure your doctor accepts Medicare insurance.