THE HUMAN EYE

Eyes are organs of the visual system. They provide
organisms vision, the ability to process visual detail, as well
as enabling several photo response functions that are
independent of vision. Eyes detect light and convert it into
electro-chemical impulses in neurons.

There are many diseases, disorders, and age-related
changes that may affect the eyes and surrounding
structures. As the eye ages, certain changes occur that can be attributed solely to the aging process. Most of these anatomic and physiologic processes follow a gradual decline. With aging, the quality of vision worsens due to reasons independent of diseases of the aging eye.
One of such cases is CATARACT.

A CATARACT is a clouding of the eye's natural lens, which lies
behind the iris and the pupil. Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. In fact, there are more cases of cataracts worldwide than there are of glaucoma, macular degeneration and diabetic retinopathy combined.
according to Prevent Blindness America (PBA).
Today, cataracts affect more than 4 million Nigerians age
40 and older. And as the population ages, more than 10
million Nigerians are expected to have cataracts by the
year 2030, PBA says.


CATARACT SYMPTOMS AND SIGNS
A cataract starts out small and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass or viewing an impressionist painting.
It makes light from the sun or a lamp seem too
bright or glaring. Or you may notice when you drive at night
that the oncoming headlights cause more glare than before.
Colors may not appear as bright as they once did.
The type of cataract you have will affect exactly which
symptoms you experience and how soon they will occur.

When a nuclear cataract first develops, it can brings about a
temporary improvement in your near vision, called "second
sight."
Unfortunately, the improved vision is short-lived and will
disappear as the cataract worsens.
On the other hand, a subcapsular cataract may not produce any symptoms until it's well-developed.

*If you think you have a cataract, see an eye doctor for an
exam to find out for sure.*


WHAT CAUSES CATARACT?
The lens inside the eye works much like a camera lens,
focusing light onto the retina for clear vision. It also adjusts
the eye's focus, letting us see things clearly both up close
and far away.
The lens is mostly made of water and protein. The protein is
arranged in a precise way that keeps the lens clear and lets
light pass through it.
But as we age, some of the protein may clump together and
start to cloud a small area of the lens. This is a cataract, and
over time, it may grow larger and cloud more of the lens,
making it harder to see.
No one knows for sure why the eye's lens changes as we
age, forming cataracts. But researchers worldwide have
identified factors that may cause cataracts or are associated
with cataract development.

PREVENTION OF CATARACT
Though there is significant controversy about whether
cataracts can be prevented, a number of studies suggest
certain nutrients and nutritional supplements may reduce
your risk of cataracts.


Good food sources of vitamin E include sunflower seeds,
almonds and spinach. Good sources of lutein and
zeaxanthin include spinach, kale and other green, leafy
vegetables.

Other studies have shown antioxidant vitamins such as
vitamin C and foods containing omega-3 fatty acids may
reduce cataract .

CATARACT TREAMENT
When symptoms begin to appear, you may be able to
improve your vision for a while using new glasses, strong
bifocals, magnification, appropriate lighting or other visual
aids.

Think about surgery when your cataracts have progressed
enough to seriously impair your vision and affect your daily
life.
Many people consider poor vision an inevitable fact of
aging, but cataract surgery is a simple, relatively painless
procedure to regain vision.
Cataract surgery is very successful in restoring vision. In
fact, it is the most frequently performed surgery in the eye clinic, with thousands of Nigerians undergoing cataract surgery each year, according to PBA.
Nine out of 10 people who have cataract surgery regain very good vision.
During surgery, the surgeon will remove your clouded lens
and in most cases replace it with a clear, plastic intraocular
lens (IOL).
New IOLs are being developed all the time to make the
surgery less complicated for surgeons and the lenses more
helpful to patients. Presbyopia-correcting IOLs potentially
help you see at all distances, not just one. Another new type
of IOL blocks both ultraviolet and blue light rays, which
research indicates may damage the retina.