My brother passed from a brain tumor in our 20's, and it was discovered when he started to have some vision problems while driving. Fast-forward just two or three years from his passing, and I started having vision problems while driving home one evening, so of course that's where my thoughts go...
Turned out to be an occular migraine, and I've continued to suffer from them on and off the last 30 years, if suffering is even what you can call it. My wife became convinced at some point early on, that a good BJ was the best cure when symptoms would appear, so there were several years where I'd honestly look forward to getting a migraine.