A few years ago, in one eye I would get blurred spot that flickered and move from center to peripheral and back. It came out of nowhere while I was driving and last about 15 minutes. It would freak me out. I had to close one eye to keep driving. One time I pulled over and waited it out. My optometrist called it an 'Ocular Migraine'. No headache associated with it. He said there is no pin point cause. They just seem to come and go. It hasn't happened lately. The body does some strange things. Your double vision is probably related to your 'Jonesing for surf' ailment.