Seeing faces when I close my eyes

Answer 1

My theory:

The retina captures light all day long and light particles don't fade out instantly.  When we first close our eyes there is that bit residual light still bouncing around our eyes.  It periodically lands on the retina.  Our brains try to interpret that light as vision but there isn't enough information so, as with our blind spot, it fills in the rest as best as it can.  The visions could just be a blend of remembered vision.