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What are soft contact lenses?
Soft contact lenses are thin gel-like lenses made from water
attracting plastics called hydrogel. They absorb water, become
soft and thus easily conform to the shape of your eyeball. However,
they don’t come without risks.
When are soft contact lenses used?
They are used for correcting vision problems in refractive eye
disorders like near sightedness, far sightedness and some types
of astigmatism.
The advantages of soft contact lenses over rigid gas permeable
or RGP lenses are:
- They are more flexible and comfortable.
- They are easier and
quicker to adjust.
- The chances of particles getting under the
lens are less.
- They rarely fall off and are easier to insert.
The disadvantages compared to gas permeable lenses are:
- Soft lenses need to be cleaned and sterilized more carefully.
- They
are more expensive and less durable than the gas permeable ones
and so have to be bought more frequently. You need solutions
for cleaning and storing soft lenses.
- Soft contact lenses
are more likely to cause corneal and other infections.
- These lenses
are not as effective in some kinds of astigmatism
What are the types of soft contact lenses?
Daily wear contact lenses: Most people wear this type of contact
lenses. They are thick or thin depending on what suits your sight
requirements. These are typically the lenses which you insert
every morning and remove every night. You should always sleep
without daily wear contact lenses. If properly cleaned and stored
these lenses should last a year.
Extended wear contact lenses: These are thin lenses having higher
water content and higher oxygen permeability. So more oxygen can
enter your cornea even when you are sleeping. Therefore, you can
wear them continuously for seven days.
The better quality lenses made from silicon hydrogel can be worn
for up to 30 days. The 30-day lenses are more rigid and so more
uncomfortable. Also, the 30-day lenses are more likely to have
scratches than the 7-day ones, which are removed every 7 days.
Extended wear lenses are more likely to cause corneal infections
than the daily wear ones due to poor lens care, bacterial stagnation
and long periods of reduced oxygen supply.
Disposable contact lenses: Disposable contact lenses are designed
for short-term use. Depending on their composition, these lenses
can be replaced daily or used for periods up to 3 months and thrown
away.
They need to be cleaned every night unless they are extended
wear types. They are less likely to cause corneal infections and
need less cleaning than the other types of soft lenses. However,
they are more expensive than the regular contacts.
How to get soft contact lenses
You can wear soft contacts only after it is prescribed by an
eye doctor. To get full benefit follow the doctor’s instructions,
like checking periods, strictly. Initially there will be slight
discomfort. If the discomfort is more immediately see your doctor.
What precautions should I take with soft contact lenses?
- Wash your hand with soap before handling the lenses.
- Use only
lens care solutions to clean the lenses.
- Avoid using lenses
while swimming. It can cause infection.
- Whatever the lens type
remove them before sleeping.
- Insert the lenses before applying
make up. Avoid lash-building mascara since particles can get
under the lenses. Mascara
may also permanently discolor your lenses.
- Use aerosol sprays before wearing
the lenses.
- Immediately see your doctor in case of irritation,
pain, redness, burning or indistinct vision.
What are some problems with soft contacts?
Soft contacts may cause:
- Eye infections if you don’t take proper care of
the lenses.
- Allergic reactions due to solutions and contaminants
in or on the lenses.
- Eye inflammation.
- Scratched cornea
A common problem among wearers of contacts is corneal infection.
This is unavoidable since all lenses, even those with the highest
oxygen permeability, are a barrier to the normal supply of oxygen.
And reduced oxygen supply is one reason for corneal disorders.
While soft contact lenses have high permeability, their hydrophilic
nature makes them absorb liquid which reduces their oxygen permeability.
Corneal disorders are therefore more likely among wearers of soft
contact lenses.
Conclusion
Soft contact lenses offer increased convenience and comfort.
But they are more prone to corneal infection than the rigid lenses.
So you need to look after them well and follow all the doctor’s
instructions. To reduce the risk of contamination, remove the
soft contacts, even the extended wear ones, before going to sleep.
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