These are dreams in which you go directly from being awake to dreaming, without losing consciousness.

I only learned about them recently. I have them but I never realized that they were a type of lucid dream.

Basically, I start seeing images before I fall asleep, but I am awake and completely aware that I am lying in bed. Then I just sort of step into the images and become part of a dream.

I always just thought of it as a pleasant way of falling asleep, as I would only step into the dream if the images were nice and relaxing.