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:: CONTACT
LENSES :: |
Contact Lenses are simple to wear and care
for, and are almost undetectable. They are thin discs of
plastic, curved on the inside to fit properly onto the surface
of the eye, and shaped on the outside to correct and improve
defective vision, for bandaging the eye after surgery, and
cosmetic benefits e.g. to cover white scarring of the eye or
to change the colour of the eye for fashion. With advancing
technology Contact Lenses can correct all forms of visual
defects including Astigmatism safely and comfortably. There
are basically two types of contact lenses : Rigid and Soft.
Both types come in varying materials with different levels of
oxygen permeabilities. The higher the oxygen permeability the
better it is for the eye.
Contact Lens care is the
most important part of contact lens wear. Good eye care also
includes proper care of the lenses. All types of contact
lenses should always be kept clean, disinfected and hydrated.
Lens hygiene is the key to a comfortable wear. All contact
lenses accumulate a variety of deposits, from the eye itself
whilst wearing them, and from the environment. The tears of
the eye contain proteins, lipids (oily secretions) , mucous
and calcium. The environment also contributes towards building
up of these deposits especially on soft lenses. The chemical
pollution from cars, factories etc., dust, metal in the air
get embedded onto the surface, causing harmful contamination
on the lens surface, over a period of time. In order to
prevent these deposits, all contact lenses should be cleaned,
soaked and disinfected daily.
These deposits on the
contact lens surface can contaminate the lens surface causing
recurrent infections, red eyes and papillae (pimples) in the
inner lining of the upper eyelids. These contaminants get
firmly bound on the lens surface as the lens gets older ( from
three months of acquiring new contact lenses, or earlier
depending on the wearers tears and environmental conditions.)
and cause severe eye problems and reduced vision,
inconveniencing both the wearers and the practitioners. Hence
a new system of prescribing and manufacturing contact lenses
has been introduced now in India - Frequent Replacement -
which enables the replacement of lenses on Daily, Weekly,
Monthly, and Three Monthly basis. The advantages of this
system of prescribing is that, frequent infections due to
protein deposits and environmental pollution are almost
eliminated, the eye gets more Oxygen, Vision and Comfort are
greatly increased, and best of all, simple cleaning systems
like multipurpose solutions can be used
safely.
Aftercare of contact lenses is the most
important part of contact lens wear. All types of soft contact
lenses get contaminated within 24 hours (when not in the eye),
due to the water contained in the material. To prevent this
from happening they should be disinfected daily.
Hypoallergenic solutions formulated for sensitive eyes are the
best and safest for the eyes. Daily cleaning by rubbing in the
palm of the hand with a surfactant cleaner is important , as
well as the weekly protein cleaning, to prevent infections due
to lens contamination.
Contaminated contact lenses are
very dangerous and a serious threat to the eye. Careless
handling can be sight threatening. A good contact lens
specialist will spend time to properly educate the patient
regarding the cleaning and disinfection of their lenses and
have at their disposal proper instruments for fitting and
supply of contact lenses. It is this combination of good
advice and service that makes it possible to adapt to contact
lenses successfully and safely. Always take advice from a
properly qualified contact lens specialist to tell you which
lenses are suitable for your eyes after examining them
thoroughly. |
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TYPES OF CONTACT LENSES
With major advances in materials, millions of people
have discovered that contact lenses are a safe, comfortable,
convenient and affordable alternative to spectacles. Contact
lenses are thin, domed discs made of complex plastic
materials, and are positioned in front of the transparent
outer layer of the eye called the cornea, to focus images onto
the retina at the back of the eye. There are basically two
types of lenses : |
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1. Rigid Gas
Permeable (RGP) RGP lenses are semi-rigid lenses made
usually from acrylate and fluorosilicon, a plastic which allow
oxygen through to the eye. They are clinically the best as
they allow maximum oxygen to reach the cornea being smaller in
size. They are easy to care for, durable and give good clarity
of vision. They can be prescribed for all types of vision
correction, including high astigmatism, bifocals, post surgery
(RK, PRK,& Lasic), therapeutic, and cosmetic for all age
groups. In certain cases these lenses are also prescribed for
myopia control. |
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2. Soft lenses Soft
lenses are made from water-absorbing plastics, which make them
pliable and membrane-like for maximum comfort. They are ideal
for sports as they cannot be easily dislodged from the
eye. New silicon based
soft lenses allow maximum oxygen to the cornea, enabling
overnight continuous wear safely for a month. With modern
manufacturing techniques, soft lenses can be made to correct
all types of refractive errors and many types of lifestyles.
Soft lenses are available in toric (to correct astigmatism),
bifocal, weekly disposable, monthly disposable, daily
disposable, extended wear and cosmetic to cover corneal scars,
as well as to change the colour of one's eyes for fashion. |
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To read Frequently Asked
Questions on Contact Lens Click Here |
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