Standard plastic lensesconsist of the plastic compound CR-39. CR-39 stands for "Columbia Resin #39," the 39th plastic produced by Columbia Resin, the business that created the polymer. Then there are glasses lenses made ofpolycarbonate. Polycarbonates, a synthetic plastic first developed in the ...
PMMA (acrylic resin), PC (polycarbonate), COC (cyclo-olefin copolymer) and COP (cyclo-olefin polymer), and some plastic materials are used for plastic lenses.
What are lenses?A lens is a transparent piece of glass or plastic with at least one curved surface. It gets its name from the Latin word for "lentil" (a type of pulse used in cooking), but don't let that confuse you. There's no real reason for this other than that the most ...
Glasses used to be made of glass. Now, most are made of plastic. Plastic lenses are lighter and can be treated with coatings to protect your eyes. But plastic is more likely to scratch than glass. Other glasses can meet specific needs: Polycarbonate or Trivex lensesare great if you, or ...
has a dome made of polycarbonate, a material with crystal-like transparency, resistant to scratches and UV rays. Contrary to what many people imagine, a transparent polymer is not necessarily PMMA. The latter would not have been a good choice for manufacturing our compasses because it is more ...