
advantages | disadvantages
| do
you like wearing glasses?
| how contact
lenses correct vision
The vast majority of people requiring vision correction can
wear contact lenses without any problems. New materials and
lens care technologies have made today's contacts more comfortable,
safer and easier to wear. Consider the questions and answers
below to help assess whether they're a choice you should consider.
Contact lens wear may be difficult if:
- Your eyes are severely irritated by allergies;
- You work in an environment with lots of dust and chemicals;
- You have an overactive thyroid, uncontrolled diabetes,
or severe arthritis in your hands; or
- Your eyes are overly dry due to pregnancy or medications
you are taking.
After a thorough eye examination, your suitability for contact
lenses and the specific contact lens option that best meets
your requirements will be determined.
What
are the advantages of wearing contact lenses?
- Many wearers feel that contact lenses show their eyes
in a better light or don't like the appearance of eyeglasses.
- Better vision correction due to the reduced obstruction
from eyeglass frames.
- They provide excellent peripheral vision.
- No fogging up in warm rooms.
- No splattering during rain showers.
- Less hassle as they don't get in the way during sports
and other recreational activities.
What
are the disadvantages?
- Contact lenses require getting used to. New soft lens
wearers typically adjust to their lenses within a week.
Rigid lenses generally require a somewhat longer adjustment
period.
- Except for some disposable varieties, almost all lenses
require regular cleaning and disinfection, a process that,
although requiring only a few minutes, is more than some
people want to undertake.
- Some types of lenses increase your eyes' sensitivity to
light.
What lifestyle do you lead? What kind of work do you do?
For those involved in sports and recreational activities,
contact lenses offer a number of advantages. In addition to
providing good peripheral vision, eliminating the problem
of fogged or rain splattered lenses, and freeing you from
worries about broken glasses, contact lenses also mean you
can wear non-prescription protective eye wear. Looking sideways
through the lenses of glasses leads to prismatic effects because
you are not looking through their centers. Your eyes have
to coordinate differently to cope with this. This does not
happen with contact lenses because you always look through
the centers of the lenses as they move with your eye movements.
Your occupation and work environment should also be taken
into consideration. People whose work requires good peripheral
vision may want to consider contacts. Those who work in dusty
environments or where chemicals are in heavy use are likely
to find spectacles more comfortable.
Do
you like wearing glasses?
Do you like the way glasses feel? Do you like how you look
in them? No longer is it really necessary to choose between
either contacts or glasses. Some of today's contacts are so
easy to wear that you can use them intermittently -- for special
occasions, while participating in sports or to match your
fashions.
New single-use, one-day disposable lenses are comfortable
and do not require cleaning. They may be easily interchanged
with glasses.
How
Contact Lenses Correct Vision
Contact lenses are designed to rest on the cornea, the clear
outer surface of the eye. They are held in place mainly by
adhering to the tear film that covers the front of the eye
and, to a lesser extent, by pressure from the eyelids.
As the eyelid blinks, it glides over the surface of the contact
lens and causes it to move slightly. This movement allows
the tears to provide necessary lubrication to the cornea and
helps flush away debris between the cornea and the contact
lens.
Contact lenses are optical medical devices, primarily used
to correct nearsightedness, farsightedness, astigmatism and
presbyopia. In these conditions, light is not focused properly
on the retina, the layer of nerve endings in the back of the
eye that converts light to electrochemical impulses. When
light is not focused properly on the retina, the result is
blurred or imperfect vision.
When in place on the cornea, the contact lens functions as
the initial optical element of the eye. The optics of the
contact lens combine with the optics of the eye to properly
focus light on the retina. The result is clear vision.
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