I had one last night.It's like sparkling lights lights in the central vision field then it moves to the side of your vision. I usually just lie down with the lights off and wait for it to pass,usually about twenty minutes or so.I never get headaches after it.First time it happened to me was about twenty years ago,It was rather frightening the first time it happened,no idea what it was.Went to the doc who said see the optician,he described it the symptoms perfectly as he suffered the same! So there ya go had about six attacks in ten years...