I have also been having the burred vision issues, with a type of tunnel vision, distortions and sort of blind spots, episodes last about half a hour. I was getting them up to two times a day, with maybe a very slight headache afterwards (note that I never get headaches, except possibly after drinking way too much). They started ten years ago, at the time my sister who is a nurse said to try zinc as she said some men my age (45+) can need more zinc as they get older. I then took a zinc tablet every day and the episodes stopped completely (at that time I had been experiencing the blurry episodes daily for over a year). Now after nearly ten years of no episodes they returned to around once a day (usually while in front of the computer, but not always). I have now doubled my zinc dose and this seems to have reduced them to a couple of times a week. Yes, I have been to few doctors, none seemed to be interested in my problem…they said it did not fit the symptoms of anything serious and said to keep taking the zinc if it worked, they also offered to refer me to a neurologist.  Note that the zinc I took (Herron Zinc Complex) has other ingredients such as magnesium, vitamin A and B6 and some other stuff that may have been playing a part.   Might try the apple as a previous poster recommended, although I eat apples often. I would be interested in what others have found useful if anything before I go to a neurologist for what will probably turn out to be an expensive wasted effort.