2009年1月8日星期四

The Return of Extended Wear Lenses

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.

The auther writes articles on different topics. To get more articles on contact lens visit http://www.contactlenseclub.com/contacts/

































































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