One morning last October I woke up and was seeing slightly blurry. That lasted for about 2 weeks and went away. A month later I started seeing double and my left eye was crossing. I went to the hospital and they took did a vision test and ran a Cat Scan. Both came out fine and I was told to see an opthamologist. My symptoms went away and come back now and again. Two weeks ago I saw the opthamologist who prescribed prism lenses for me. Although they did help at first, my eye started crossing again last night and the lenses don't seem to aid me at all. FYI, I don't have headaches at all. Can someone tell me what the problem might be?