Columbia Resin 39
An alternative material to polycarbonate is CR39 (Columbia Resin 39), a plastic polymer commonly used in the manufacture of eyeglass lenses. Unlike polycarbonate, CR39 requires a UV coating to be added to protect eyes from the sun’s harmful rays.
Does CR-39 block UV?
Results: All the tested lenses absorbed all of the UV-B and at least 99% of UV-A. Conclusions: These data suggest that UV tinted CR-39 lenses provide protection against UV radiation that meets the ANSI Z80. 3-1996 Standard for non-prescription sunglasses and fashion eyewear.
What lens has the highest Abbe value?
CR-39 lenses
CR-39 lenses have a high Abbe value of 59.3 making them the lenses with the least distortion from dispersion/chromatic aberration.
Are blue light filter glasses effective?
ROSENFIELD: Both of the studies actually found that the blue-blocking filters have no effect, no significant effect on digital eye strain. This didn’t really come as a major surprise to us because there really is no mechanism whereby the blue light should be causing digital eye strain.
Do high index lenses break easily?
High index lenses tend to be more brittle than the average pair of glasses. They may scratch and even shatter more easily than their other counterparts but there are usually anti-scratch coatings which can be added if necessary.
What is CR-39 used to measure?
CR-39 is now a trade-marked product of PPG Industries. An alternative use includes a purified version that is used to measure neutron radiation, a type of ionizing radiation, in neutron dosimetry.
What is a CR39 detector used for?
In the radiation detection application, CR-39 is used as a solid-state nuclear track detector (SSNTD) to detect the presence of ionising radiation. Energetic particles colliding with the polymer structure leave a trail of broken chemical bonds within the CR-39.
What is crcr-39 glass?
CR-39 is about half the weight of glass with an index of refraction only slightly lower than that of crown glass, and its high Abbe number yields low chromatic aberration, altogether making it an advantageous material for eyeglasses and sunglasses.
What does cdcr-39 stand for?
CR-39, or allyl diglycol carbonate (ADC), is a plastic monomer commonly used in the manufacture of eyeglass lenses. The abbreviation stands for “Columbia Resin #39”, which was the 39th formula of a thermosetting plastic developed by the Columbia Resins project in 1940.
