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How Radars & Radar Detectors Work

Radar is an acronym for radio detection and ranging. - Tim Robinson
 

Is the Navajo Nation President Being a Hypocrite about Uranium Mining?

James Finch visited New Mexico to study first hand why Navajo Nation president Joe Shirley Jr. banne ... - James Finch
 

Phone Conferencing Equipment

With the advent of Phone Conferencing, taking your business global is quite an easy task. With the i ... - Alison Cole
 
 

Nickel Base Alloys in High Demand

Nickel based alloys such as Monel 400, Inconel 718, Inconel 600, Inconel 625 have widespread industr ... - Brendan Cryns
 

POV in Writing (Humor by Josprel)

The term, "POV," always reminds me of "PVC" - the lengthy, six-inches wide, fiberglass pipes that we ... - Joseph Perrello
 

Let There Be Light, Part 1 - The Camping Lantern

The only thing worse than setting up a tent in the rain is setting up a tent in the rain in the dark ... - Nick Smith
 

Illegal Aliens in Los Angeles at Car Washes

Why do Illegal Aliens come to America? Well, many come for the higher pay and send money back to the ... - Lance Winslow
 

Wheelchair Ergonomics for Computer Users

Ouch! Bad ergonomics is a real pain in the neck, but solutions, even for wheelchair users, don't hav ... - Rodney Robbins
 
 

Index » Science & Space » Discovery
 

Invention of the Contact Lens

 
Author: Charlie Cory
 

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.

 
 
 

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