Question

why do we see stars when somebody hits us in the face?

Answer 1

This happens because of confusion in your brain of what is going on. The reason we can see is because there are cells in our eye that pick up light. When they pick up light, they send a signal to the brain and the brain deciphers what we are seeing.

The problem is, sometimes other stimuli can cause these eye cells to fire. If you give a strong enough stimulus (such as being punched in the face or just applying a good amount of pressure on your eyes), those eye cells will send a signal to the brain. The thing is the brain always thinks that when these eye cells are firing, it is because they are seeing light. So your brain tells you you are seeing light in random spots. This is why you see "stars" when you get hit in the face!

Answer 2

Many people say they 'see stars' when flashes of light occur in their field of vision. The stars may look like fireworks, lightning bolts, or camera flashes.

Seeing stars is usually the result of a disturbance either in the retina or in the brain.

It is much more likely that the problem is related the retina.

This thin lining of cells in the back of the eye sends messages to the brain when light is detected.

When the blow lands, our skull will snap back, at which point it will hit the front part of our brain.

This rapid movement of the skull and its impact on the brain is what causes us to “see stars”, because the occipital lobe is where the visual cortex is located.