I've never had Optic Neuritis, however since the summer of 2007 (when my major, major relapse was in full swing) I woke up to blurry/doubled vision. Noticed as soon as I turned on the TV and sat down to watch the weather channel. I couldn't read the bottom line anymore!
2 rounds of IVSM since.. I'm fairly certain I'll remain with the double vision until I see the eye specialist or maybe (cross fingers) find the right med or procedure.
Yes, vision issues are a very common MS symptom.