"fireworks?"

Like an earlier poster, I see what look like tiny 'fireworks' of light in my vision against a bright background such as the sky. They are not readily apparent and they are not noticable under dim conditions. Someone said this is a symptom of 'detached retina' but isn't that more like a pronounced 'shower' of sparks in bright >and< dim conditions?

What I see is barely noticable until someone points it out. They look like squiggly fireworks that spin and shoot across the line of vision for just a second or so. I told my wife to stare at the sky and concentrate to see if she could see this. She said she could see squiggly lines shooting around. I've had my eyes checked and the doctor said my eyes and retina are healthy. Then what is this we're seeing? Is there a name for this phenonmenon? What causes it? Does anyone know what in the world i'm talking about?