Why Do We See Stars When We Bump Our Heads?
The “Stars” we see if we receive a hard blow on the head are really a sensation of light caused by the nerves of the eye. Whenever our eye nerves are stimulated in any way, we have the sensation of light. Usually, it is light that stimulates the nerves of sight, but these nerves can be stimulated by other things, such as a blow on the head.
Whenever the eye nerves are stimulated by a hard blow, the nerves flash a message to the brain. The brain interprets this “bump” message as a burst of light. Most people describe this reaction as “seeing stars.” Our head is a very important part of our body because that is where the brain is. The brain controls all the rest of our body so we need to look after it as much as possible.
The brain is made of soft tissue and the skull is hard and bony. Between the brain and the skull there is a ‘cushion’ of fluid which helps protecting the brain. But, if there is a sudden hard knock to the head, the brain could knock against the skull. This can bruise the brain so that it works differently for a while. This is called a concussion. There could also be some bleeding inside the brain.
Concussion can last for a moment or two, or a person could be knocked out for much longer. If someone is knocked out for a long time they are said to be in a coma. Most times that we bump our head we may feel a bit dizzy for a while but may have a headache for some time.