I hear ya, Bullwinkle. Not a dumb question. Medicare sends you a thick booklet but they don't answer basic questions. Like, for example, where do I go for sick call?
We went through this a few years ago. With civilians everything is referrals. You can't just go see the guy who can fix you. You first have to go to something like a senior health center. Take a look at 211.com or something like that. You can find the nearest senior health center. Tell them you want an appointment because you're feeling ill, or have an ingrown toe nail, or whatever. Anything to get in the door.
I even tried VA. Now there's a joke. For VA you have to be broke or already in their system (disability or service-connected).
For eye problems -- start out with an optometrist and he'll refer you to a Medicare MD for glaucoma, cataracts, etc.
Take all your prescriptions to the nearest military pharmacy. No co-pays. Can't beat it.