Plastic Lenses
High-Tech Lenses for the Digital Age
Most people refer to this lens type as "Regular" or "Plastic" Lenses. The patent
of CR-39 allyl diglycol carbonate monomer in 1945 marked a key
milestone in the history of the optical industry. This new optical monomer
inspired a great deal of creativity and ingenuity, which led to many of
the great plastic lens products available today.
Plastic lenses made from CR-39 allyl diglycol carbonate monomer
combine the optics of glass with the excellent mechanical, thermal and chemical
resistance properties of a thermoset material. CR-39 monomer is used
for casting plastic lenses for prescription eyewear, sunglasses and other
plastic products requiring high abrasion resistance and high quality optical
properties. Plastic lenses from CR-39 monomer give less chromatic
aberration compared to polycarbonate lenses, as measured by the Abbe number.
The lens is light weight compared to glass, and may be made in just
about any prescription, though many people with higher prescriptions prefer to use
Hi-Index Lenses. The higher the index,
the thinner the lenses.
Plastic lenses are great for prescription sunglasses due to their tintability
factor and you can virtually tint a plastic lens to any color under the rainbow.
CR-39 is a trademark of PPG Industries, Inc.
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