There's an easy way to catch those wavy visual signals that follow an intense experience when one wakes up. The hypnopompic imagery.
I put a sheet of white paper on the wall by the side of my bed to write things without having to stand up, but I notice sometimes whole texts on it, and I can't quite read them, but it's fun. The surface of the paper seems like a screen for the imagery.
All the walls and ceiling here are painted white, but I only notice the imagery on the paper. I guess you'll need a certain amount of light getting into your room for you to be able to see at least the paper. The things that will appear on it have their own light.
I don't know whats the use for this, but maybe you could find one.