My retrosigmoid surgery to remove a 3 cm AN was on May 12, 2011 and I still have nystagmus. I had double vision but it cleared up on its own about 4 weeks ago. But I still have nystagmus. I noticed it while doing some eye exercises that I was given in my vestibular therapy. I would move my eyes from left to right and then right to left without moving my head. I noticed that at the end of the movement when my eye was to the right, that it felt like my eye was still moving. Well, it is. My physical therapist and my neuro-opthalmologist both confirmed it. Since my double vision cleared up, my neuro-opthalmologist said there was nothing to do for the nystagmus, but continue the exercises I am doing, try to ignore it and work around it, and it should clear up on its own. I was not given a timeline on when my nystagmus would become "unusual" if I still had it. I've told my neurosurgeon, my corneal ophthalmologist, and my neuro-opthalmologist about the nystagmus and they weren't surprised nor overly concerned. None of them said, oh you'll have it for a few weeks but if you still have it a year after surgery, that's not good. Like I said, none of them said that or mentioned a timeline.
It is annoying though. I haven't been back to work yet because of balance and walking issues, but I imagine that the nystagmus will bother me as I am an editor by occupation. My job requires sitting in front of a computer all day, reading. I've noticed I can't focus on anything while in a moving car, or when I'm in a busy environment. I end up getting really exhausted. I think it's a combination of the nystagmus and my balance problems. I haven't tried driving yet, because my reflexes are not good enough yet to attempt it. So we'll see whether the nystagmus affects that when the time comes.
I think it's a good idea to continue your exercises. It's good to hear you don't have balance issues and that you'll be running a marathon!