CORNEA: The cornea is the clear front
surface of the eye that covers the colored part
of your eye (iris). It is similar to the front
window of your camera. The cornea is comprised
of five layers: Corneal epithelia, Bowman's membrane,
Stroma, Decemet's membrane, and the endothelium.
The stroma is the tissue which is ablated during
laser surgery (see laser surgery page).
IRIS: The iris is the colored portion of
the eye. It is similar to the aperature of a camera.
The iris regulates the amout of light entering
the eye. During dilation, drops increase the size
of the pupil so that your Today's Vision doctor
can evaluate the health of the eye internally.
LENS: The lens is similar to the lens in
a camera. It provides the focusing ability of
the eye. At the age of 40-45, presbyopia presents;
this is when the lens begins to lose its focusing
ability and a bifocal may be required. When the
lens becomes opacified or cloudy, it is termed
a cataract. The vision with a cataract can be
simulated by trying to view through a stained
glass window. A cataract can be removed and replaced
with an artificial lens implant.
MACULA: The macula is a small area located
at the back portion of the retina. It is comprised
of cones and functions in crisp 20/20 central
vision. Diseases that affect this area can cause
a decrease in vision. Disease processes such as
macular degeneration, retinal detachments, diabetes,
and hypertension can potentially cause blindness.
Dilation allows your Today's Vision doctor the
ability to inspect the macula more fully.
MUSCLES: Ocular muscle alignment is critical
in developing sharp three- dimensional vision.
During a routine eye exam, an eye care professional
evaluates the integrity of the muscles and the
nerves which supply them. Eye turns and double
vision should be evaluated by your Today's Vision
doctor.
NERVES: The visual pathways of the eyes
are equivalent to the
co-axial cable that connects your video camera
to the VCR. These nerves transmit visual information
from the retina to the occipital lobe of the brain
where the information is processed. During a routine
eye exam an eye care professional evaluates the
integrity of these nerves. Through examination
brain lesions such as tumors and aneurysms can
be detected in many cases.
OPTIC NERVE: The optic nerve is similar
to the cable that connects your video camera to
the VCR. The images seen in the eye is transported
to the occipital lobe of the brain where the image
is processed. (See picture--topic: nerves). The
optic nerve head can be seen by an eyecare practitioner
when the eyes are dilated. Your doctor evaluates
the nerve for such disease processes as glaucoma,
papilledema (increased pressure in the brain),
multiple sclerosis or brain tumors.
RETINA: The retina is similar to the film
in a camera. This is where the picture seen by
the eye is converted to electrical signals and
then transported to the occipital lobe via the
optic nerve. The retina is made of cells called
rods and cones. Rods are primarily used to aid
with night and peripheral vision, while cones
are designed to aid with color vision and crisp
20/20 vision.
SCLERA: The sclera is the white portion
of the eye. It is comprised of tough connective
tissue that gives the eye its shape.
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