[Kde-i18n-vi] Raven Media - Invention of the Contact Lens

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Invention of the Contact Lens



The invention of the contact lens dates back before 1877, when Adolf Fick,
Eugene Kalt and August Muller made the first contact lens from glass.
Leonardo da Vinci created sketches encapsulating the concept of a covering
for the eye as early as 1508.

In 1801, Thomas Young decided to work on a device to help correct his own
vision. What Young did was to fit a water-filled glass tube with a
microscopic lens. However, it would be a number of years before anyone
developed a device that could fit onto the eye itself.

So we come to that date, 1887. Fick, Kalt and Muller made the first known
contacts from thick glass, which covered the entire eye. As one might
imagine, such an object was not very comfortable to wear. However, they were
able to correct some vision problems, but because of the comfort issues,
patients could not keep the lenses in their eyes for more than a few hours.

In the early part of the last century, scientists came to the rescue. In
1934, a new plastic called polymethylmethacrylate (PMMA) was created, which
was to revolutionise the development of contact lenses. Patents were issued
in 1948 to Kevin Touhy for the first PMMA contact lens, the first hard lens.
These lenses were much easier to fit and wear than their earlier
counterparts, and rather than fit to the whole eye, PMMA lenses were small
enough to just fit the cornea. During the early 1960's, the use of contact
lenses boomed, and the majority of contact lens fittings were carried out
using PMMA hard lenses.

Then, in 1971 Bausch and Lomb introduced their first soft contact lenses to
the United States. Soft lenses were made of very thin and pliable material,
which was heavily water based. Comfort levels in contact lens wearers
increased dramatically, and long duration lenses became the norm. However,
whilst still much more comfortable than their PMMA counterparts, soft
contact lenses were not perfect. They eyes are a living organ, and require
oxygen in order to remain healthy. Despite their increased comfort, soft
contact lenses were unable to allow enough oxygen into the eye.

So, science came to the rescue one again, and with the aid of silicon as a
core material, rigid gas permeable (RGP) contact lenses were created. As
their name suggests, gas permeable lenses let oxygen through to the eye,
helping them remain healthy, even through extended wear. Some of the comfort
issues re-emerged, because rgp lenses are hard and take a little getting
used to. However, the effort is often worth while because they are better
for the health of your eyes.

The article was written by Charlie Cory, who is the owner of FX Eyes, a
website dedicated to providing advice about buying special effects contact
lenses online.

http://www.invent-tech.com/
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