For quite a long time I have had episodes of double vision lasting usually between 3 and 5 months, and recurring every few years. I have had MRI's and neurology tests which ruled out MS, diabetes, tumour and all the usual causes of double vision. I now have a situation where I have perfect vision while my head is still but as soon as I move my head my vision is double, then returns to single when head is still again. This causes difficulty with such things as driving and walking across streets, and makes playing sport impossible. Do you have any ideas on what may be causing it? I do not experience headaches at all. I have visited an opthomologist many times and he has no idea at all why this is occurring. Prism glasses were okay for previous episodes but now are not effective as my vision is fine till my head moves. Please help!!