Double and blurred vision?!

For about 3 years now, I will occasionally experience blurred or double vision. It doesn't happen often but when it does, I can only describe it as looking through binoculars while you are adjusting the settings if that makes any sense. The thing that gets me is that it will do it several times a day for a few weeks and then stop for a few months. I've been to eye doctors and even specialists who seem to find nothing wrong. The doctors I've seen were baffled actually. It seems like if I am focusing on something like the television or computer and then I direct my attention elsewhere, that is when it happens most but sometimes it just happens out of nowhere. Any ideas? Ask for more details if you need to and thanks in advance for any answers.