As a teacher and a doctor, I talk
about the eye on a daily basis to my optometry students and patients
alike. I often use examples that my optometry students and patients can
relate to. The eye is like a high definition video camera that captures
images of the visual world in real time. If any part of your eye, that
is, your “human video camera,” is affected or broken you may experience varying
degrees of blurry vision, discomfort, or other common symptoms.
If you seek professional evaluation by your optometrist
at the first inkling that something is out of sync, he or she can “fix or
repair” your eye and get you back on a healthy track.
So let’s talk about the eye from
front to back.
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| Anatomy of Human Eye - cross section |
To start, the eyelids and
lashes are the first visible structures to the outside observer.
Not only are the eyelids and lashes beautiful, but they also serve to protect
the eye. The eyelidsspread lubricating tears like that of a
windshield wiper across the surface of the eye with just a single blink, and
the lashes act like specialized antennae sensing the smallest
incoming offending particles.
Next, the conjunctiva is
known to us as the “white” part of the eye. This too is visible to the
outside observer. There are times that the conjunctiva may
get inflamed or infected which results in that unwanted “pink eye” or
conjunctivitis.
Much respect and attention has been
given to the 5-layer-thick cornea as the clear window of the
eye. This is the layer where contact lenses are applied to correct
nearsightedness or farsightedness. Many successful surgeries like LASIK
and corneal transplants have been performed on this tissue.
The anterior chamber and
the vitreous are two compartments that give form to the eye
and serve as conduits for circulating important fluids from one part of the eye
to another.
The color part of the eye is called
the iris. It comes in many different colors and hues
including brown, hazel, green, blue, and even violet. The purpose of the
iris is to regulate the amount of light that enters the eye. Like that of
a camera shutter, the iriscontrols the size of the pupil thus
preventing under or over exposure of the picture of the visual world that is
being seen.
The crystalline lens sits
right behind the iris. And similar to a camera lens, the human lens helps
focus the things we see.
The retina, optic
nerve, and macula can all be found way back in the
eye. The retina is the nervous tissue of the eye and is
made up of 10 important layers. It gathers nervous signals and funnels it to
the optic nerve. As the name implies, the optic nerve is
the nervous cable that connects the eye to the sight center in the back of the
brain. Themacula allows you to see the finest details in
vision.
This sums up the crash course on the
Anatomy of the Eye 101. Next time you are at your friendly optometrist’s
office, just imagine the different parts of your eye being systematically
looked at.
prepair by;
~By Judy Tong,
OD
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