|
Contact
lenses are thin, curved plastic disks designed
to cover the cornea, the clear front covering of
the eye. Contacts provide a safe and effective
way to correct vision when used with care and
proper supervision. They can offer a good
alternative to eyeglasses, depending on your
eyes and your lifestyle.
Why do people choose
contact lenses instead of spectacles?
People wear contact lenses for various reasons.
Contact lenses typically provide better vision
than spectacles for some visual conditions such
as severe short-sightedness [myopia],
long-sightedness [hyperopia],
astigmatism, corneal distortion , or after
cataract removal [aphakia].
Some people like the wider
field of view provided by contact lenses, as
side vision [peripheral vision] is often
blocked, obscured or limited by spectacle
frames. Contact lenses do not fog up with
changes in temperature - or from perspiration -
and they are unaffected by
rain . Many people choose contact lenses
because they think glasses make them look less
attractive or they find spectacles annoying.
Sports players and people involved in vigorous
activities often find contact lenses more
convenient than spectacles, especially for water
sports and contact sports. Priests,
psychologists and many others also find that
contact lenses avoid the barrier effect that
spectacles may cause, thus leading to more
direct eye-contact.
Types of contact lenses
Soft contact lenses are lenses made of
hydrophilic (water-loving) plastics that absorb
liquids. When these materials soak up liquids,
they become soft and mold to fit the eyeball.
Soft lenses can correct many visual problems.
They are quite different from gas permeable
lenses. Types of soft contact lenses.
Daily-wear soft lenses
are the most comfortable, and your eyes
will adjust to wearing them in less time than
with hard contact lenses. Soft lenses may be
worn during vigorous physical activities and
playing sports with less likelihood that the
lenses will slip out of place. Daily-wear lenses
must be removed, cleaned and stored every day.
Disposable contact
lenses
Disposable contact lenses are lenses which are
designed to be replaced on a
regular basis ,
usually either daily, bi-weekly or monthly. The
more often a lens is replaced, the less the lens
will become deposited with proteins and oils.
Many of the problems that contact lens wearers
experienced when contact lenses were replaced on
an annual or two yearly basis are seldom seen
nowadays. Disposable contact lenses are
therefore a healthier
alternative . Daily disposable contact
lenses are a great option for people who only
want to wear their contact lenses a few times
per week, for example, for sport. They also
remove the need for cleaning, since they are
inserted in the morning (or before you play
sport) and then thrown away afterward, offering
exceptional convenience and good value for
money. Lenses, which are replaced two-weekly or
monthly, are good value
if you want to wear lenses everyday.
Leave-in (extended wear)
contact lenses
Leave-in (extended wear) contact lenses are
designed to be worn continuously for 30 days and
nights and then replaced with a new contact
lens. They offer the ultimate in convenience ,
since they usually don't need removing or
mechanically cleaning. Other advantages include
being able to see without struggling to find
your glasses if you get up in the night, or not
having to worry about removing lenses with dirty
hands if you go camping. You also won't need to
remember to carry bottles of solutions around
with you if you go out with friends and end up
staying out the night!
Toric Contact
Lenses
Have you been told you can't wear
soft contact lenses
because you have
astigmatism ? You have the option! Toric
contact lenses are made from the same materials
as regular ("spherical") contact lenses, Toric
lenses have two powers in them, created with
curvatures at different angles (one for
astigmatism, the other for either
myopia or
hyperopia ). There's
also a mechanism to keep the contact lens
relatively stable on the eye when you blink or
look around. To provide crisp vision, toric
contact lenses cannot rotate on your eye.
Gas permeable contact
lenses
Gas permeable contact lenses are usually used
for the correction of moderate levels of
astigmatism. They provide
excellent clarity of vision , especially
in cases where the astigmatism is irregular
(such as with keratoconus). They require a
longer period of adaptation than soft lenses.
Gas permeable contact lenses offer
excellent long-term corneal
health since they allow almost as much
oxygen to pass through to the cornea as without
a lens on the eye. Many of the problems
associated with the reduced oxygen flow through
the old-style "hard lenses" are seldom seen
nowadays due to the developments in these modern
gas permeable materials.
PROSTHETIC CONTACT LENS
*
It is used in patients with corneal
disfigurations, corneal scarring and decentered
pupil
Some handy tips for safe,
comfortable contact lens wear :
* Never wear lenses
longer than
prescribed. Do not wear daily lenses while
sleeping.
* Do not wear your
lenses overnight
unless recommended your contact
lens practitioner. Overnight wear of contact
lenses increases the risk of complications.
* Always
wash, rinse, & dry your hands before
handling lenses. Avoid pump & moisturizing
soap & use lint free cotton towels and
tissues.
* Do not use
saliva to wet
your lenses. Do not put lenses in your mouth.
* Use only
approved contact
lens solutions for lubricating or wetting your
lenses.
* Always use
fresh solutions
in your lens case when disinfecting your lenses.
* Ask your contact
lens practitioner about wearing lenses during
water activities
and other sports. In some cases alternative
lenses may be prescribed for sport, other
hobbies and activities.
* Schedule and keep
follow-up appointments
with your contact lens practitioner.
* Never use
non-sterile home-prepared saline. The use of
home-prepared saline with contact lenses has
been associated with serious infections.
* Contact lens
storage cases
can be a source of bacteria and other microbial
growth. Lens cases should be cleaned, rinsed,
and allowed to air dry each time the lenses are
removed. Replace the lens case frequently.
* If your eyes become
red, irritated, painful, abnormally light
sensitive or if your vision worsens while
wearing lenses, immediately remove the lenses
and consult a contact lens practitioner.
* Do not get lotions,
creams, sprays or chemicals in your eyes or on
your lenses. It is best to insert lenses
before applying make-up and remove them before
removing make-up. Water- based and gel-based
cosmetics are less likely to damage lenses than
oil-based products. Do not apply eyeliner on
the inside rim of the eyelids.
* You should have eye
examinations every six to 12 months or as
recommended by your contact lens practitioner.
* Contact lenses wear
out with time and should be
replaced
regularly.
* Disposable lenses
should be thrown away
after the recommended wearing period
prescribed by your contact lens practitioner.
Daily disposable lenses should not be re-used.
|