Thread: What causes HI...

I have read that when you shut your eyes light still penetrates through your eyelids and the shapes you see is actually blood, your brain then makes you see it as shapes and scenes etc.
Does anyone know if this is true or not??

Not true. HI happens in the dark too.

Since it is often used as a link from waking to the dream state (some WILD techniques), we can assume that it's "dream imagery". The brain slowly switches from the external to internal visual input. That's why some people experience being pulled or pulling themselves into a strong hypnagogic image to find themselves in a dream.