Interesting, for me it happens sometimes if I'm badly hungover. Instantly after closing my eyes, I start seeing cartoon-like shapes that rapidly mutate to something different. Usually it's faces of people. The shapes are very dim, and black and white. But I really do "see" them as they were there.

Now I want to attempt using the technique in TFA to improve this "skill", also interested in using this for falling asleep faster and maybe even to successfully using the WILD technique for lucid dreaming, which I was never able to do.