Perhaps it's some form of pseudo-astral projection, where your consciousness becomes detached from your body and might allow you to see THROUGH your eyelids, in this case. I've had it happen to me once before (about two to three months back) when waking up in the afternoon. Assuming it was a spontaneous projection, it might have generated the mind split effect and you were, for a short time, existing consciously on two separate levels.

I've seen the same effect linked to the development of psychic abilities, but it's a far shot. Not too sure on the psychic side of things. Still, it's interesting. I'm wondering if a person can forcibly split their personality while projecting/dreaming, maybe with a left-brain/right-brain mental split.