External Anatomy Of The Left Human Eye
The human eye is a complex organ that allows us to perceive the world around us. The external anatomy of the eye includes several key components, each with a specific function.
1. Orbit: The eye sits in a protective bony socket called the orbit.
2. Extraocular Muscles: Six extraocular muscles in the orbit are attached to the eye. These muscles move the eye up and down, side to side, and rotate the eye.
3. Sclera: The extraocular muscles are attached to the white part of the eye called the sclera. This is a strong layer of tissue that covers nearly the entire surface of the eyeball.
4. Conjunctiva: The surface of the eye and the inner surface of the eyelids are covered with a clear membrane called the conjunctiva.
5. Tear Film: The layers of the tear film keep the front of the eye lubricated. Tears lubricate the eye and are made up of three layers. These three layers together are called the tear film.
6. Cornea: Light is focused into the eye through the clear, dome-shaped front portion of the eye called the cornea.
7. Anterior Chamber: Behind the cornea is a fluid-filled space called the anterior chamber. The fluid is called aqueous humor.
8. Iris and Pupil: Behind the anterior chamber is the eyes iris (the colored part of the eye) and the dark hole in the middle called the pupil. Muscles in the iris dilate (widen) or constrict (narrow) the pupil to control the amount of light reaching the back of the eye.
9. Lens: Directly behind the pupil sits the lens. The lens focuses light toward the back of the eye. The lens changes shape to help the eye focus on objects up close.
10. Eyelids: The upper and lower eyelids form a moist region around the eye, and protect the surface of the eye from injury, infection, and disease.
11. Eyelashes: The eyelashes are the hairs that grow along the edges of the upper and lower eyelids. The eyelashes protect the eye from foreign particles, such as dust, pollen, and debris.
12. Meibomian Glands: Meibomian glands are the oil glands located inside the eyelids. Their opening pores line the edges of the eyelids, near the eyelashes.
Each of these components plays a crucial role in the overall function of the eye. They work together to protect the eye, control the amount of light that enters, and focus that light onto the retina, allowing us to see the world around us..