Starring at Light too Long

In lab I sat on the stage and my classmates focused the lights on me so the instructor could show us cool things with light. So as I'm sitting there looking at the lights I look away to talk to a friend and all I see is a blue dot as there head and a red ring around that. But I could see like the sides and there was no blue dot with a red ring. It was only when I focused on something like to read something or a picture I would be able to see it right.