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Information On The History Of Wearing Glasses

Glasses can be traced back in our history as far as the

thirteenth century. The first signs of glasses lenses were

found in elementary crystals or convex shaped glass that

have been found in archeological digs dating back several

thousand years. It is believed however that these shaped

"lenses" were not used for any eyesight correction of

glasses lenses, rather they were used most probably as

magnifiers. It wasn't until much later, likely the first

glasses as such were developed in the mid-thirteenth

century from convex lenses. The term lenses itself is most

likely derived from the latin for "bean" as the slightly

convex shapr of the bean resembles a basic lens for

spectacles.

The earliest lenses used in any sort of glasses known were

made of quartz crystals and could be used for correction of

vision as well as simply magnifying.

As their viability as glasses became more widely known and

so popular, the process to make the glasses lenses

developed first into spectacles made from hand blown glass

- and later (likely the very end of the thirteenth century)

into shaped glasses whereby molten glass was formed into a

convex mold and so defined a lens that could be used as

glasses or spectacles for correction.

It is also believed that some Roman Emperors had lenses

formed into a type of spectacles that were made of

emeralds, and so became what were probably the first

prescription sunglasses.

The real development of glasses as documented however was in

Italy and were produced by craftsmen who were used to making

jewelry and so able to incorporate small crystal lenses into

structure that could support them in front of the eyes

without having to be held.

Of course this made the earliest glasses extremely expensive

as they were handmade by artisans and used glass which was a

very expensive material in the 14th and 15th centuries. The

first actual documented wearer of glasses however was the

Bishop da Provena in the 13th century who had some simple

magnifying crystals connected to short handles and then

joined together so that they could be balanced on his

nose.and became at the same time the first example

of "pincenez".

There remains today some dispute about the origins of

glasses and spectacles, as there is some evidence that

Marco Polo encountered them when exploring the East and

landing in China in 1270 or 1271. There is further credit

give then by the Chinese themselves to the even earlier

development of glasses - or at least of a practical

corrective (non-magnifying) lens to Arabia as much as a

century earlier.

Despite this somewhat disputed provenance, there is no doubt

as to the popularity that glasses enjoyed as the manufacture

of them became less of an artisan skill and more of a

manufacturing process using glass and being predictive of

the lens curvature and so correction for myopia in

particular.

It is interesting to note that although there is good

documentary evidence of glasses being produced in some

fairly significant volume in the 16th century - it was not

until much later in the early part of the seventeenth

century that the physics of the lens was actually understood

and how the correction for myopia actually came about. This

discovery or explanation is credited to Johannes Kepler who

studied optics for several decades, eventually publishing

his work in 1604.

The Determination of the Necessity for Wearing Glasses

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