What keeps the eyeball from collapsing?

The eyeball is a ball-shaped organ that is located in the front of the skull. It is made up of several layers of tissue, including the sclera, the choroid, the retina, and the vitreous humour. The sclera is the outermost layer of the eyeball and it is a tough, white, fibrous tissue that helps to maintain the shape of the eye. The choroid is the middle layer of the eyeball and it is made up of blood vessels that supply the eye with oxygen and nutrients. The retina is the innermost layer of the eyeball and it is made up of light-sensitive cells that convert light into electrical signals that are sent to the brain. The vitreous humour is a gel-like substance that fills the space between the lens and the retina. It helps to maintain the shape of the eye and it provides optical clarity.

The eyeball is kept from collapsing by the intraocular pressure (IOP). The IOP is the pressure exerted by the fluids within the eye. The IOP is maintained by the balance between the production and drainage of aqueous humor, a clear fluid that is produced by the ciliary body. When the IOP is too low, the eyeball can collapse. This condition is called hypotony. When the IOP is too high, the eyeball can become hard and painful. This condition is called glaucoma.

The IOP is a critical factor in maintaining the health of the eye. If the IOP is too low or too high, it can damage the optic nerve and lead to vision loss.