Yes, vision does get worse with age, although I think short-sightedness is pretty stable during adulthood. I had had a stable vision measurement for years before ME/CFS and it didn't change after either. The 'blurriness' somehow didn't show itself with a standard eye chart where you have one thing to focus on and time to work things out. I don't know if the difficulty seeing detail when driving has something to do with the overwhelming cognitive demand? It also seems to fluctuate in severity.I think floaters are pretty common and like shortsightedness increase with age.
That's the problem. These things sound like things that everyone gets, and certainly something that everyone who is getting older gets, and they are hard for individual people without expertise in vision science to really pin down. But, they do affect quality of life, and more importantly, they might be clues. It shouldn't be impossible for people who know about vision and have some equipment to hand to plan studies that can tell us if these vision issues have something to do with ME/CFS.