About 21-22 years ago I had a bout of having all colors washed out and not really registering in my vision. It was strainge - I could still see colors after a fashion but I had to think about them, and everything was greyed out. I was in a major funk at the time and subsequently attributed it to depression. Now I am not sure that it wasn't the MS. In the mid to late 1990s I had some trouble with my eyes, like a shimmering in my peripheral vision. I chalked that one up to eye strain - again, I'm not sure it wasn't MS. In the last few years before the diagnosis, I have had more trouble seeing at night and had severe double vision when diagnosed last year. The double vision was caused by a brain lesion though, not optic neuritis.
Since the diagnosis, I have changed the way I eat. Not only has the night vision problem largely gone away, my daytime vision has become sharper and more vivid (at least with my glasses on, like you I am very near-sighted and have been that way since I was a little kid). The improvement in vision from diet changes (if that is what caused them) took several months. Right now my only vision annoyance is little floaters - they come and go.
I don't know if I can really say diet improvement cleared up my eyesight or it is just the ups and downs of MS. I'd sure like to think it was diet. Melody has suggested that diet has seemed to help her husband.
Good luck with it, that is, may the vision disturbances GO AWAY!