About Rigid Gas Permeable Lenses
What They Are And What They Can Do For You.
Finding out about about rigid gas
permeable lenses is starlight forward these days, courtesy
of the Internet. So what are rigid gas permeable (RGP) lenses?
Potted History Of RGP Contact Lenses
When contact lenses were first introduced,
they were made of a material called PMMA. PMMA (polymethyl methacrylate)
is a versatile polymeric material that is well suited for many imaging
and non-imaging microelectronic applications. Don't worry about
the technical jargon. Suffice to say, that PMMA was once used for
hard contact lenses.
The biggest problem with PMMA lenses was that
they were uncomfortable, and difficult to get used to. One of the
biggest reasons for this discomfort was that PMMA lenses were not
gas permeable, which means that they did not allow oxygen to pass
through them. Eyes need moisture and oxygen, and without either
of these things, they will complain.
Gas permeable (GP) contact lenses, or RGPs,
are significantly more advanced than their PMMA counterparts from
years gone by. The most significant advance has been in their permeability,
which allows oxygen to pass through them. They eyes of today are
very happy about this.
Soft contact lenses were introduced to the
market in the early 1970's, and overcame some of the discomfort
issues because they were not hard and more comfortable to wear.
At least in the short term. However, the eyes were still being starved
of oxygen, so the problem was not being resolved, just postponed.
Gas permeable lenses were introduced in the
mid-1980s and were made in part of silicone. Silicone makes a more
flexible plastic than PMMA, and silicone is also gas permeable,
so oxygen can pass through then. Eyes suddenly became more receptive
to these types of lenses, and many of the issues associated with
the discomfort of hard contact lenses disappeared.
But RGPs also provide many other benefits.
RGP's actually help you see better. Their
rigid nature means that corrections made in the prescription are
more accurately applied to the eyes. RGP's also last much longer.
Soft lenses are very thin and are susceptible to tears and other
damage. RGPs have increased resistance to dirt deposit over soft
contacts. They can be easier to clean, and since they're long-lasting,
they can be much less expensive soft contacts over a period of time.
There are still comfort issues with RGP lenses,
and it can take time to get used to them. However, RGPs over improved
correction for astigmatism
sufferers, and have been shown to offer better health for the eyes
in clinical tests.
To get the best from RGPs and to give your
eyes a chance to get used to them, you should wear them every day.
Failure to do this could result in perennial discomfort.
Taking
care of your eyes |
