4. The retina is the film of the eye. It converts light rays into electrical signals and
sends them to the brain through the optic nerve. The sides of the retina are
responsible for our peripheral vision. The center area, called the macula, is used for
our fine central vision and color vision. The retina is where most the problems
leading to vision loss Occur. Three of the leading causes of blindness, from retina
damage, are Retinitis Pimentos, Macular Degeneration and Diabetic Retinopathy
5. IRIS
This is the colored part of the eye: brown, green, blue, etc. It is a ring of muscle
fibers located behind the cornea and in front of the lens. It contracts and expands,
opening and closing the pupil, in response to the brightness of surrounding light.
Just as the aperture in a camera protects the film from over exposure, the iris of the
eye helps protect the sensitive retina.
6. LENS
During modern cataract surgery the outer membrane of the lens is left in
place. The artificial intraocular lens is placed in this sack
7. CORNEA
The cornea is a clear, dome-shaped surface that covers the front of the eye. It is
the first and most powerful lens in the eye's optical system. To keep it transparent
the cornea contains no blood vessels. Tears that flow over it and aqueous humor in
the chamber behind it keep it nourished. When you hear of eye banks and eye
transplants, it is the cornea that is being replaced. The cornea can be damaged
from: accidents, infections, and genetic defects.
9. HYPERMETROPIA
Hypermetropia, also known as
farsightedness, long-sightedness,
is a defect of vision caused by an imperfection in
the eye (often when the eyeball is too short or
the lens cannot become round enough), causing
difficulty focusing on near objects, and in extreme
cases causing a sufferer to be unable to focus on
objects at any distance. As an object moves
toward the eye, the eye must increase its optical
power to keep the image in focus on the retina. If
the power of the cornea and lens is insufficient,
as in hyperopia, the image will appear blurred.
11. MYOPIA
Myopia, commonly known as being
nearsighted or shortsighted, is a
condition of the eye where the light that
comes in does not directly focus on the
retina but in front of it. This causes the
image that one sees when looking at a
distant object to be out of focus, but in
focus when looking at a close object.
14. CARE OF EYE
1- DO NOT SEE VERY BRIGHT SOURCE
OF LIGHT
2- DO NOT READ IN VERY DIM LIGHT
3- WASH EYES WITH COLD WATER
4- DO NOT RUB EYES IN CASE ANY
THING HAS FALLEN IN.
5- CONSULT EYE DOCTOR IN CASE OF
EYE PROBLEM.
