I've noticed this ever since it started happening back in Feb, and was the first symptom that lead me to the neurologist DXing me with MS. The times that my vision goes double, blurred or unfocused/dizzy is when I'm in a vehicle, like riding with someone since I haven't driven a vehicle in over 2 months now. It's like after I even get out of the vehicle from that short or long ride, doesn't matter the length, I still feel my vision is impaired.

Does anyone know why this is?

Because the car is moving, and your eyes can't track the movements fast enough, it makes any diplopia (double vision) worse.

I had diplopia a couple of years ago. My eye doctor took opaque scotch tape and put it on my glasses, on the glasses lens for the eye that was causing the diplopia. Covering the glasses lens with the tape, basically made a patch, so that I was only looking out with one eye. It really helped, and was a heck of a lot more comfortable than wearing an actual eye patch, which I've done before.

The tape didn't hurt the lenses of my glasses.