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There was a time when all eyeglass lenses were made of glass. Glass
lenses have brilliant optical quality but they are thick and heavy. However an
alternative to glass lenses was plastic lenses, which are more comfortable,
lightweight and were introduced in the 1940s. Plastic lenses offer similar
optical performance to glass lenses and are about half the weight.
Plastic remains the most popular lens material for eyeglasses in the United
States, accounting for over 50 percent of all lenses sold. But though plastic
lenses are lighter than glass lenses, they too can be thick especially in
moderate and strong prescription powers.
Many thinner, lighter lens materials have been developed for eyeglasses in
recent years. These are called high index lens materials as they have a higher
Index of refraction than regular glass or plastic lenses. Lenses made with high
index materials are considerably thinner and more attractive than regular glass
or plastic lenses of the same prescription power.
High index lenses are available in both glass and plastic materials. High index
glass lenses are thin, but they are much heavier and can break more easily than
high index plastic lenses.
Each lens material has a unique set of features and benefits that you can view
as follow:
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High index plastics
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If you want the thinnest, most attractive lenses then this is best. |
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If the lens is thinner then the refractive index is high and also
the cost. |
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Most high index plastic lenses provide 100% protection from the
sun's UV rays. |
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For the best optical performance and appearance anti-reflective
(AR) coating is necessary.
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High index glass
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They are over twice the weight of high index plastic lenses of the
same thickness. |
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Some high index glass lenses do not meet the minimum Impact
resistance standard required by the U.S. Food and Drug Administration (FDA). |
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They are tremendous scratch resistance. |
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Less than 2 percent of eyeglass lenses sold in the U.S. are made of
high index glass.
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Polycarbonate
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If you want the safest and/or lightest lenses possible then it is
the best choice. |
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They are over ten times more impact resistant than regular plastic
lenses. |
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They are used in safety eyewear, sports spectacles as well as
general-purpose eyewear. |
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It is recommended for children's eyewear and whenever eye safety is
a primary concern. |
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It is up to 40% thinner and 30% lighter than regular plastic
lenses. |
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It provides 100% protection from the sun's ultraviolet (UV) rays. |
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The second most popular lens material in the United States,
accounting for approximately 20 percent of all eyeglass lenses sold.
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Plastic
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It is the most economical lenses possible. |
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It has outstanding optical clarity if compared to glass lenses. |
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It is not recommended for high prescription powers due to
thickness. |
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It can be easily tinted to dark sunglass shades. |
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It is the most popular lens material in the United States,
accounting for over 50 percent of all eyeglass lenses sold.
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Glass
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It has heavier lenses at a relatively low price. |
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Glass lenses don't require scratch-resistant coatings for added
durability. (All other lens materials do.) |
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It is twice the weight of other lens materials. |
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It is recommended only for mild prescription powers due to thickness and
weight.
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Keep in mind that to assure all of your visual and lifestyle needs,
it's usually best to purchase more than one pair of eyeglasses.
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Eyeglass Frame material
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To find eyeglasses with the qualities you require is as simple as
choosing a frame material. There are different materials and each one comes
with its own unique set of strengths that makes it discrete.
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Plastic
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Zyl (zylonite, acetate, or Cellulose acetate) is a material that is
a very cost-effective and creative option for eyewear and is extremely
lightweight. It can be designed with single, multiple, or even layers of
colour. Zyl eyeglass frames are the most prominent of the plastic eyeglass
frames in use today. |
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Nylon is used in sports and performance eyeglass frames because it
is virtually unbreakable and relatively lightweight. The material is, however,
difficult to adjust and can be manufactured only in darker colours. It has a
higher tolerance to hot and cold as well. |
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Polycarbonate is 10 times more impact-resistant than glass and is used for
children's, sports, and safety glasses. Polycarbonate lenses are thinner and
lighter than glass lenses, and the material comes with built-in ultraviolet
protection.
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Metals
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Titanium is lightweight, durable, strong and corrosion-resistant.
It can be made in a variety of colours for a clean, modern look. All the
titanium frames are not 100 percent titanium as some frames are made from an
alloy that is a mixture of titanium and other metals, like nickel or copper.
However, if the frame is known "Titanium", and is of higher quality, then these
frames are also safe for those who have had acidic reactions to metals frames
in the past known as hypoallergenic. |
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Aluminium frames are lightweight and are corrosion-resistant. It is
not only the world's most abundant, but also the most widely used, nonferrous
material. Pure aluminium is soft and weak, but commercial aluminium with small
amounts of silicon and iron is hard and strong. Although they are very
lightweight, it is difficult to join or weld to different designs limiting its
adaptability. |
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Solid silver or sterling silver is not commonly used as a mainframe
material because it doesn't make comfortable frames so many times these metals
are used ornamentally on plastic frames. |
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For a luxurious touch semi-precious or precious stones are sometimes used as
accents in frames, especially in the temples. Most popular choices are onyx and
turquoise, however diamonds can also be used. Rhinestones are diamond made from
rock crystal or glass or paste are a less expensive alternative and are often
used to create a retro look. |
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Stainless steel frames are lightweight, low toxicity and are strong
they are also nickel-free and thus hypoallergenic. It's an alloy of steel and
chromium and may also contain another element. Most stainless steels contain
anywhere from 10 to 30 percent chromium, which imparts an excellent resistance
to corrosion, abrasion and heat.
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| Today modern eyeglass frames are available in a huge variety of
styles, sizes, and materials. Children's and safety frames are now available in
materials that are nearly indestructible. New materials and design technology
have made frames more lightweight and comfortable. Good quality frames are now
available in all price ranges, too at buymeglasses.com. |
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