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If you are one of the regular users of the contacts you
must be very well aware of the daily regimen with the lenses. Come back
home, remove the lenses carefully, rinse them, disinfect them and place
them carefully in the lens case.
However, this
is routine for those who wear the daily-wear lenses, and not with the
extended wear ones. This other type is nothing too far different from
the ordinary daily-wear lens, the only difference being that these can
be worn overnight.
It was around 1981 that the overnight wearing
of contacts was recognized as medically acceptable by the experts. In
the beginning one could keep the lens on for as long as two weeks at a
stretch. Later, encouraged by the results, the permissible limit was
extended to 30 days. However, the honeymoon did not last long and the
researchers found that the likelihood of infections was far more
pronounced in those who wore them overnight.
Consequently, the
maximum approved wear duration shrunk to seven days. But even that was
looked upon with suspicion, for in the opinion of a number of experts,
overnight wear itself was way too dangerous. So, soon most of the eye
specialists started cautioning the users against the overnight use of
the contacts.
However, the extended wear lenses have staged a
comeback. These lenses have comeback riding on the wave of disposable
lenses, which reduces a few risks. Since one has to replace them
periodically, the chances of harmful deposits are curtailed. Earlier the
lenses were to be cleaned and disinfected regularly but one had to
continue with them for a few years before replacing them. In such cases,
the possibility of infection increases.
Now, when the lens has to
be replaced weekly, one begins with a new lens every week, which cuts
down the probability of infections. The advent of silicone hydrogels has
also been helpful in bringing the extended use lenses back as they
enable enhanced oxygen inflow, which decreases the chaces of infections
further.
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