Easta: I too get migraines but only about every 6 months. I had a retinal migraine once, and the symptoms were exactly what you described. I went to my eye doctor b/c I thought something was wrong with my vision and he said "You have a migraine in your eye." ?? I said "How?" and he told me that you can actually get a migraine anywhere in your body where there are blood vessels. He told me mine may or may not progress to a headache stage after the eye stuff. It did and it turned out that the eye stuff was the "aura" that some migraine sufferers get. I never thought I was one of the aura people b/c I always got my migraines in the morning and woke up in full blown migraine. The doctors think now that I probably get the aura while I'm asleep. I've had a couple since then that came on during the day and I did experience the aura both times, although slightly differently each time. I didn't realize what was happening until the headache arrived. Unfortunately, by the time I get there I am unable to treat it - can't keep any meds down and the dissolving kind don't work for me, so I've had to go to the ER sometimes when I can't tough it out long enough.
I also have a family history of stroke, aneurysm, and TIA, so they keep a pretty close watch on my head with CTs periodically. You may want to have your doc do one if they haven't yet.