I've been having similar vision problem without the headaches since 1998. It happens so randomly aI can't link a pattern to it. It ust happened to me 15 minutes ago and it is already gone. I found this site because I wanted to figure out what was happening. My episodes only seem to happen about 3 to 10 times a year. An earlier post  seemed to think it was a nutritional imbalance. I tend to agree. Todays episode happened after eating food that I don't normally eat anymore. The first time this happened I was freaking out and ran to burger king and ate a ham and cheese cresandwich hashbrowns and a coke and the symptoms were gone in a few minutes. Everytime after that I woukd eat some sort of nutritious food and the symptoms would subside. Strawberry yogurt has worked. I never tried candy nor would I. Today I just let it take its course while reading these posts and it lasted about 15 minutes. I have to say whenever I start a diet plan to lose a little weight and diet with good food to maintain my weight. I never have the problem. Today though I stepped off and ate a bunch of fried food for lunch and here I am trying to figure out what is going on. I was happy to see that other people have had similar experiences because any doctor I have talked to has had no answers