| Eye care lab . com
Eye care information on diseases and treatments
Eye biology introduction
The eye is a complex structure that works the best when all parts are functioning as part of the whole. Without the eye a human being has no sight.
The eye is an orb that is manipulated by attached muscles. The outer layer of the eye is called the sclera. The sclera is thick, white tissues that encases all of the orb except for the opening to the cornea.
Components of the eye
It is inside of the sclera that we find all of the basic components that enable us to see. These essential components of the eye include --
The eye is also equipped with all kinds of different ways to protect itself from damage. The eyelids and eyelashes prevent foreign objects like dust from falling into the eyes. The eyelids also act like windshield wiper and help smear tears across the eye to cleanse it. Tears are a saline fluid that is produced by the lacrimal glands situated just under the upper eyelids
Tears also produce a thin film over the eye to keep it lubricated. The tears must be kept moist in order to keep the cornea transparent and free from infection.
Orbit of the Eye
The boney structure that contains the organ of the eye is called the orbit. The orbit serves the dual function of protecting the eye and allowing it freedom of movement.
Process of vision
Light enters the eye through the pupil. The lens located mid way in the eyeball focuses rays of light using an array of tiny eye muscles called the cilary body. These ciliary muscles allow the lens to change shape so that the light entering the pupil always hits the retina. The photosensitive rods and cones inside the retina absorb the light and convert them into electrical impulses, which are then carried along the optic nerves to the brain where they produce an image. During the process of seeing the eye is always focusing and refocusing so that electrical impulses can be sent to the brain to produce an image.
The image that is produced on the retina is always upside down but the brain ultimately interprets it as being right side up.
Each human being has two eyes so that things can be viewed in three dimensions. Each eye captures a different view of an object to produce depth of field. Depth of field allows us to gage the distance, depth and size of anything that we are viewing.
Sight is a sense that few people can do without. It is estimated that almost 80% of our learning is facilities through eyesight. Understanding how the eye functions helps you understand how to keep your vision healthy.