Transparent Quartz
Posted in Uncategorized on 04/27/2010 07:48 pm by admin
Eyeglass Lenses-Then And Now!
The history of eyeglasses goes back to the magnifying glass, which was invented in the early 1200s. The first optical lens used for aiding sight was made from a transparent quartz and a hard, crystalline mineral called beryl. The reflective surfaces were ground to certain angles, which had been discovered could enhance vision.
As the demand for eyeglasses grew, quartz and beryl lenses were virtually replaced by glass lenses. The convex – or outwardly curving lens – was the first optical lens used in glasses to aid the correction of far sightedness, but other corrective lenses followed, including the concave – or inwardly curving lens – for the correction of near-sightedness.
The glass lens prevailed for both prescription glasses and sunglasses until 1952, when plastic lenses were introduced. The plastic lens grew rapidly in popularity because the lens was lighter and less liable to break. Now of course, nearly all the glasses worn today have plastic lenses.
Although the manufacture of plastic eyeglass lenses far exceeds the manufacture of glass lenses, it’s interesting to see that the process has remained much the same for both types. Both plastic and glass lenses are produced by successive stages of fine grinding, polishing, and shaping. Again, the same process is used to produce lenses for telescopes, microscopes, binoculars, cameras, and various projectors.
In the past, opticians relied on separate optical laboratories to produce eyeglass lenses. Today, there are a number of full-service optical outlets that produce lenses for customers on-site. The process of obtaining the right prescription glasses lens is now simply a matter of entering the details via an online opticians, then choosing from an endless range of frames made from materials as diverse as plastic or titanium.
You can even try them out ‘virtually’ on screen, to see what they would look like being worn! Then once the process is complete, they are dispatched so that within a day or so, they are sitting comfortably on your face, doing what all eyeglasses have always ever done, whatever material was employed to create the lenses!
About the Author
www.specsandglasses.com are one of the premier online suppliers of a huge range of both branded and non-branded high quality prescription glasses and accessories with some of the lowest prices in the industry.
Run by a team of highly trained, experienced and qualified staff from technical sales advisors through to highly experienced laboratory technicians making up your prescription glasses to the highest of standards, they are 360 degree dedicated customer service.
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