Phosphenes


The things you see when you close your eyes and rub them hard or push them on.

A phosphene is characterized by perceiving some form of light when there is little or no light actually entering the eye, making it an entopic phenomenon (meaning the source of the phenomenon is within the eye itself). Phosphenes are most commonly introduced by simply closing your eyes and rubbing them or squeezing them shut, tightly; generally the harder you rub or squeeze, the more phosphenes you'll see.

This pressure stimulates the cells of the retina and, thus, makes your brain think you are seeing light. Specifically, Grüsser et al. demonstrated that pressure in the eye results in activation of retinal ganglion cells in a very similar way to how they activate as a response to light.