Your IOP can vary at different times of the day, but it normally stays within a range that the eye can handle. American Academy of Ophthalmology. As fluid pressure within your eye increases, it damages these sensitive nerve fibers and they begin to die.
No guarantees. Read an overview of general eye anatomy to learn how the parts of the eye work together.
This drainage system is a meshwork of drainage canals around the outer edge of the iris. As mentioned above, in front of the receptors are layers of cells through which the light must pass. As the fluid builds up, it causes pressure to build within the eye.
The tough, fibrous nature of the sclera also protects the eye from serious damage — such as laceration or rupture — from external trauma. Although it might seem purely cosmetic, the iris actually functions to adjust the size of the pupil.
Tears drain from the eye through the tear duct. The sclera is the white part of the eye that surrounds the cornea. An alternative is to use a half silvered mirror that covers the complete entrance area and allows half the light ener the eye and then allows half of the reflecting light to pass through the mirror into the observers eye.
Are You at Risk For Glaucoma? When you look directly, or fixate, at a stimulus you the retinal locus of this central fixation is the fovea.
The amacrine cells also exhibit lateral connections in this inner plexiform layer. Back Print. The extraocular muscles are attached to the white part of the eye called the sclera. Continue on to Chapter 9. Advanced Search. Small fibers called zonules are attached to the capsule holding the lens, suspending it from the eye wall. Muscles in the iris dilate widen or constrict narrow the pupil to control the amount of light reaching the back of the eye.
This is a strong layer of tissue that covers nearly the entire surface of the eyeball. These muscles move the eye up and down and side to side, and rotate the eye.
Reviewed By: When there is very little light, the pupil expands so it can soak up as much as possible. Here is a tour of the eye starting from the outside, going in through the front and working to the back. A clear, delicate membrane called the conjunctiva covers the sclera.