Piano - my husband had the same problems about ten years ago. One day I noticed that one eye was dialated and the other was like a pin point. We called the doctor and they referred him to an Eye specialist. They did some type of test that showed he did not have a tumor or anything like that. I don't remember the medical name they used but the doctor said he just had a "lazy pupil", and that it would probably eventually return to normal, and it did, I can't remember just how long he had it but he also did have very bad headaches with it, still has the headaches even though both pupils look normal now. I think the doctor was a neuro-optomologist here in Portland at the Casey Eye Institute.