NoraNeko Reviewer
Eye is an opaque ball averaging 2-3 cm in diameter. The refraction system of the eye consists of the cornea, the crystalline lens, the aqueous humor and the vitrous humor. Most of the refraction of light entering the eye occurs on the cornea.
Major Parts of the eye used for seeing:
1. Iris
Colored circle of the eyes.
Its main task is to regulate the size of the pupil by contraction or relaxation of its muscles.
It has been claimed that each iris is unique and is a better identifier than fingerprints.
2. Pupil
The black circle that we see in the middle of the eyes.
An opening through which light enters the inner portion of the eye. It changes size to regulat ethe amount of light entering the eye. In dim light, it enlarges to allow more light to pass through. In bright light, it becomes smaller to minimize incoming light.
3. Sclera
The white background.
It provides structure, protection and strength to the eye.
4. Conjunctiva
The thin, transparent tissue that lines the inner surfaces of the eyelids and the outer surfaces of the eyeball.
Inflammation of the conjunctiva is called conjunctivitis, a condition which makes the white parts of the eyes appear red.
5. Cornea
Window of the eyes.
Outer thin, transparent membrane of the eyeball.
It protects the eyes and refracts most of the incident light that enters it.
6. Ciliary Muscles
Attached to the crystalline lens and are responsible for changing the shape of the lens when focusing on objects at different distance.
7. Crystalline Lens
Behind the pupils is a clear convex structure.
It can focus on objects at different distances by changing shape. This ability of the lens is called accomodation.
8. Optic Nerve
Carries image from the retina to the brain.
9. Aqueous and Vitreous Humor
Aqueous is between the cornea and the lens.
Vitreous is on the other side of the lens.
Both humors are responsible for giving the eye its near perfect spherical shape. They also belong to the refractive system of the eyes.
Fovea is an important part of the retina.
Blindspot is the point in the retina where the optic nerves exit.
Choroid is betwen the retina and sclera.