GLASSES : RESPECTED BY THE OPHTHALMOLOGISTS
Glasses are regularly the simplest solution for al lot of ocular problems. Glasses have sometimes possibilities that lenses or surgery don't have . This can be explained during a consultation. You can obtain a consultation by clicking on the red link here under :
FIRST QUESTION: GLASS OR PLASTIC
Since the Middle Ages one knows "mineral glass" (in short: "glass") prepared from sand with silicium (= a mineral) . Since the rise of organic chemistry they can also make plastic glasses with excellent optical qualities. We speak disrespectfully of "plastic" glasses. Better speak of "organic" glass.
WHAT ARE THE MAJOR BENEFITS OF ORGANIC GLASS
ORGANIC GLASS IS NOT BREAKABLE:
ADVANTAGE:
- They are used for delicate montages (such as rimless eyeglasses).
- Children play wildly . This is the best reason to take organic glasses: The organic glasses (almost) never break. So your childs eyes will not be damaged by glass splinters.
PHOTOCHROMATIC GLASSES ARE POSSIBLE IN ORGANIC GLASS
So they are prettier and discolor faster than mineral glasses. Moreover, you can't see it are photochromatic glasses inside,because they discolor completely clear!
ORGANIC GLASS IS LIGHTER
ADVANTAGE: for people with higher diopters, athletics, people with sensitive noses, etc.
NOTE: About the weight of the correction: the ideal combination is: organic glass in a titanium frame. Titanium is a very light and extremely strong metal . Moreover it has a high flexibility (especially in "titan flex-frames). So this is the safest frame for sports. It's also perfect for children !
WHAT ARE THE SMALL DISADVANTAGES OF ORGANIC GLASS?
1) They are slightly
more expensive
2) They are slightly
thicker (however much lighter)
3) They do not have such
great power range, but this expands each year !
4) Plastic
scratches easier than glass ! All plastic glasses come therefore almost standard with a scratch resistant layer. This makes them resistant to scratches, but not scratch free! That's why it is still necessary to pay attention for scratching:
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Wet cleaning: always use a special spray or humid wipes.
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Microfiber tissues are the best tissues to clean organic glasses : because of their very fine texture they do not damage the soft surface of plastic glass.
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Always put your glasses in their case/box if you do not need it. Never put the glass-side on a rough surface (for instance: table) . Tthat will make scratches.
VARIOUS TYPES OF ORGANIC GLASSES
ACCORDING TO THEIR REFRACTIVE INDEX (= a number that indicates how much the light is refracted by the glass - the more the light is refracted, the thinner and more beautiful the glass can be): standard is an index of 1.4 . Higher indexes are better, like 1.5 or 1.67. A refractive index of 1.71 is the max, you can get for the moment
THE SPECIFIC WEIGHT OF THE MATERIAL. The lightest glass is "polycarbonate", with an sw of 1.2. The density of different types ranging from 1.23 to 1.36, which is still very light compared with mineral glass (sw 2.4 to 3.6).
WICH ORGANIC GLASS SHOULD YOU CHOOSE?
CONSIDERATIONS:
It is obvious that a thinner glass is more beautiful but also more expensive (given the research), especially the glases with a refractieve index of 1.7 !
Polycarbonate long seemed the best choice, because of its weight, but the anti-mirror treatment s give some problems.
OUR CHOICE
After careful consideration, we recommend glasses of 1.67, as the best choice. First and foremost it is a very thin glass that can be obtained at the price of a polycarbonate glass , within a given stock range (6 to -8 dpt). Price / quality = the best!