Anatomy of the Eye


Sclera/Conjunctiva

The sclera and conjunctiva combine to form the white, outer layer of the eyeball.  These two outer layers represent the barrier that encase and help protect the eye.  The layers extend from the optic nerve behind the eye all   the way to the cornea.


Cornea

The cornea is the clear front surface of the eye.  The eyelids close and lubricate this portion to ensure that the layer remains moist and clear. This     is the first layer that light passes through as it enters an eye.


Anterior Chamber

The anterior chamber is the space between the cornea and the iris in the diagram below.  The anterior chamber is filled with an aqueous jelly that   gives the front portion of the eye its shape.

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Iris

The iris is the colored portion of the eye.  The iris is a muscle that has the important job of controlling the amount of light that enters into an eye.  In   low light situations, the iris becomes smaller making the pupil larger and allowing more light into the eye.


Pupil

The pupil is the black hole in the center of the colored portion of an eye.     The pupil is a hole that allows light to enter into the eye.  The iris controls    the size of the pupil depending on the amount of light in the surroundings.

 

Lens

The lens is the focusing portion of the eye that sits directly behind the pupil.  The lens is very thin and flexible at birth, allowing for a tremendous amount   of focusing ability.  This focusing ability gradually decreases through the course of one's life, resulting in the need for reading glasses about the age    of 40 in most people.  This is also the area of the eye in which cataracts form.



Vitreous

The vitreous is a jelly that fills the area of the eye between the lens and the retina.  Its gel-like consistency helps to provide the eye's shape.  Often the components of the vitreous jelly will clump together in strands and spots called floaters.

 

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Retina

The retina is the portion of the eye that contains all of the visual receptors.  As light passes through the eye, it is focused onto the retina to provide sharp, clear vision.  Several blood vessels run through the retina.  This is significant because the eye is the only part of the body where blood vessels can be viewed in their natural state without surgery.  It is always recommended that patients with diseases like diabetes, high blood pressure and high cholesterol have yearly dilated eye examinations so that we can examine this part of the eye.


Macula

The macula is a special spot in the retina with an extremely large amount of visual receptors.  This area is responsible for helping with our detailed visual tasks.  Things like reading, driving, and watching television utilize this area extensively.  Diseases that affect this area can be devastating to a person's ability to function in visually challenging situations.


Optic Nerve

The optic nerve is the nerve that connects a person's brain to his or her eye.  The spot where this nerve enters the back of the eye is called the optic nerve head or optic disc.  The appearance of the disc should be pinkish with a small indentation that is assessed to ensure that one isn't at risk for glaucoma.