why do eyes rarely get paralysed?


why do eyes rarely get paralysed?

In: 1

It’s because the optic nerve is very difficult to damage as it is protected by the skull. With something like a leg, you have the entire spinal cord to damage to paralyze them, with the eye, all you have is a very short nerve going straight to the brain that would need some pretty bad damage to the face to affect.

Because your eyes are so close to your brain.

with something like your legs you have a lot of room to break the connection between them and the brain.

Your eyes are practically part of your brain. Anything that leaves the eyes themselves alone and also leaves the parts of your brain alone that make you who you are, would only have a very narrow window to disrupt the connection between the two.

Any sort of damage that makes you unable to control your eyes is very likely to either destroy your eyes and or parts of the brain in the process. That would leave you blind, dead or brain damaged in addition to not being able to move your eyes and be the more important bit.

It does happen (google ophthalmoplegia) but is rare and more likely to be the result of an inherited condition than an injury.

Paralysis is often the result of spinal cord injury. Most of the “cables” (nerve tracts) that connect your brain to your muscles and somatosensory organs go through the spinal cord. The lower the muscle, the further down the spinal cord the nerve tract goes before branching out into the body. So, the higher up the damage to the spinal cord occurs, the more of these tracts that get interrupted, and the higher up the paralysis goes. If the damage is very low down, you might only get paralyzed in your legs, but if it’s higher, the paralysis might include e.g. the muscles in your pelvis, torso, arms, neck and so forth.

However, the eyes aren’t connected to the brain via the spinal cord. They send visual information to the brain via the *optic nerve*, and the brain sends motor commands to the eyes via the *oculomotor nerve*. These are two of a total of twelve so-called *cranial nerves.* The cranial nerves all connect to the brain without passing through the spinal cord, and are protected by the skull. As such, they aren’t vulnerable to neck or back injuries, which are a main source of paralysis (along with strokes and other damage to the brain itself).