Eyes and ears when I'm anywhere near shooting activity.
What's the worst that could happen without wearing hearing protection? (Assuming shooting non-suppressed):
100% chance of hearing damage. A single round fired from a 22 rifle _will_ cause hearing damage if not protected. Is it immediate? No. Is it cumulative? Yes. Is it irreversible? Yep. There are some affects that are reversible such as short-term ringing in the ears, but they're a symptom of the underlying damage which is permanent.
What's the worst that could happen without wearing eye protection?
Almost zero% chance of something actually happening. BUT (and it's a big one) the effects are generally immediate and catastrophic. If you have a ruptured case in a rifle that doesn't handle things well, you'll at least have a face full of hot gas and debris. If you're not wearing glasses, you'll be in a world of hurt to say the least. Even if you're not the one shooting, there are significant risks. I've had hot brass bounce off my face from someone shooting pistols a "theoretical" safe distance away. I've also been hit by small lead shavings from revolvers. Will it protect you from ever possible threat to you eyes? Probably not. If someone hands you someone else's 30-06 reload that is supposed to be full of 57 grains of W760, but it's full of 57 grains of Titegroup, the glasses will do little to stop the bolt from embedding itself in your skull if you're dumb enough to shoot it.
As an RSO, if I see you shooting without eye pro, you're gone. No warning, no "pretty please", nothing. If you're shooting at a range I'm running, you've already had the rules explained to you. I don't care if you've "been shooting that way for years." or "They've never enforced that before." I do a lot of BSA (scouting, not really-cheap-scope) activities and most of the people who argue are scouts who have been shooting for a while but have decided that they're invincible. If I won't let them shoot until they have eyes/ears and their leaders start arguing with me, which happens much more often than I thought it would, the whole group can get kicked out of the activity. I've only done that once, but it has happened.
So, in summary.... If you value your eyes at all, wear eye protection. If you never have an mishap where it saves your eyes, great. If you have issues with fogging or other things, take multiple sets and lots of cleaning wipes. Or shave your eyebrows to keep them from oiling up the lenses.
Just don't wear glass lenses without something over them. And most sunglasses don't count. They're not impact rated, but they're generally better than nothing.
Just my $0.02.
Matt