Have you ever closed your eyes, rubbed them and seen stars? Or
at least little pops of light? It turns out that those pops of
light have a name: phosphenes. They are a phenomenon
characterized by seeing light without light actually entering
the eye. This rubbing mechanically stimulates the cells of the
retina causing this effect. Sometimes, these phosphenes can
still be seen for moments after you open your eyes. Meditators
have also reported experiencing phosphenes, and they have
actually been known since antiquity. Ancient Greeks described
them. Other reasons people ‘see stars’ are because of sneezing,
coughing, blowing your nose or receiving a blow to the head.