As I know that not everyone can get eyeglasses with medicare. They medicare only pay for eyeglasses for people who have had cataract surgery. If you eyeglasses or contact lenses are really necessary, medicare may pay for it. However, you shall go a shop which accept medicare to get the eyeglasses.
In common, medicare are not cover eyeglasses. However, if you need eyeglasses after cataract surgery, you may use medicare to buy a pair of eyeglasses. Also, you shall go to a Medicaid optician if you want to buy eyeglasses with medicare since not all eyeglasses shop can accept medicare for eyeglasses. As for how much will medicare pay for the eyeglasses, you can call 1-800-MEDICARE for exact info.