I just renewed my license. I have glaucoma (which is under control), and had cataract surgery in both eyes several years ago. I can see well enough now to no longer need glasses for driving. But the internet horror stories about the DMV cracking down on oldsters had me worried. For no reason, as it turned out. They didn't even use an eye machine, just a chart on the wall. (Over 80 they require a form signed by a doctor).
I strong armed my dad into surrendering his driver's license after a tense drive around town that included turning into oncoming traffic on a divided road.
Regarding seasonal riding, I ride year round, but in my old age, I'm no longer willing to tough it out in cold weather.
I've never had heated gear. When I had sidecars, I'd go for rides in snow storms just for the fun of it, wearing a snowmobile suit. They handle surprisingly well, even on ice.
I can think of one reason to appreciate the notion of a "riding season". Lower insurance costs.