Although many people use their eyes to see the world around them on a daily basis, not many consider how complex their eyes really are. Some of the many parts of the eye include ones you have probably heard of before, such as the cornea and lens, and some you may not be aware of, such as the sclera and pupil. With proper care, they can all work together to allow humans to see properly.
The cornea is the clear layer of the eyeball that bulges forward. It is comprised of five layers and is quite sensitive due to the nerves that run just underneath it. The main job of the cornea is to help the eye focus.
The part of the eye that is most talked about and that is often the most familiar part of the eyeball is the iris. The iris is what one talks about when referring to the color of a person's eyes. Its main job is to control how much light enters the eye.
Located directly behind the iris is the lens. Its main job is to focus the rays of light onto the retina. People up to about 50 years of age can change the shape of the iris by exercising muscles attached to it, but after age 50, the lens can no longer change shape.
The pupil is the part in the center of the eyeball that appears to be black. It is actually the opening of the iris. The pupil is actually what lets light into the eye and contracts or expands depending on how much light it comes in contact with.
The sclera is a part of the eyeball that is quite visible but not quite well-known by name. It's the white part of the eye that, when irritated, can become red or, when jaundiced, may be tinged yellow. It's extremely strong and has tendons attached to the back of it.
Located on top of the sclera and behind the pupil is the retina. It's a layer of tissue comprised of nerves. The retina is sensitive to light; it takes images and transmits them to the brain.
The images the eye receives go to the optic nerve, which then transfers those images to the brain for processing. The optic nerve is located at the very back of the eyeball. When it is damaged, there is typically a large loss of vision, the extent of which is typically determined by the extent of damage.
It takes a lot of parts to make the eye work properly. By seeing an eye doctor annually, you can help keep your eyes functioning the way they are supposed to. Should any problems arise, such as discomfort, a change in color or if a foreign object enters it, it's important to see the eye doctor immediately.