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  2. Ballistic eyewear - Wikipedia

    en.wikipedia.org/wiki/Ballistic_eyewear

    Non-impact protectors are those which do not pass all high-impact testing requirements and are therefore marked only with "Z87" (no "+" sign). The U.S. military standard requires (at a minimum) that ballistic eyewear can always withstand a 0.15 caliber, 5.8 grain, T37 shaped projectile at a velocity of 640 to 660 feet per second (approximately ...

  3. Corrective lens - Wikipedia

    en.wikipedia.org/wiki/Corrective_lens

    Higher-quality optical-grade glass materials exist (e.g. Borosilicate crown glasses such as BK7 ( n d = 1.51680 , V d = 64.17 , D = 2.51 g/cm³ ), which is commonly used in telescopes and binoculars, and fluorite crown glasses such as the best optical quality low dispersion glass currently in production, N-FK58 made by the German company Schott ...

  4. Borosilicate glass - Wikipedia

    en.wikipedia.org/wiki/Borosilicate_glass

    Guitar slide made of borosilicate glass. Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10 −6 K −1 at 20 °C), making them more resistant to thermal shock than any other common glass.

  5. Eye protection - Wikipedia

    en.wikipedia.org/wiki/Eye_protection

    Safety glasses or spectacles, although often used as a catch-all term for all types of eye protection, specifically revers to protective equipment that closely resembles common eye wear. To meet most national standards, spectacles must include side shields to reduce the ability of debris to get behind the lenses from the side.

  6. Polycarbonate - Wikipedia

    en.wikipedia.org/wiki/Polycarbonate

    Polycarbonate is commonly used in eye protection, as well as in other projectile-resistant viewing and lighting applications that would normally indicate the use of glass, but require much higher impact-resistance. Polycarbonate lenses also protect the eye from UV light.

  7. Bulletproof glass - Wikipedia

    en.wikipedia.org/wiki/Bulletproof_glass

    Bulletproof glass of a jeweler's window after a burglary attempt. The Mona Lisa behind bulletproof glass at the Louvre Museum. Bulletproof glass, ballistic glass, transparent armor, or bullet-resistant glass is a strong and optically transparent material that is particularly resistant to penetration by projectiles, although, like any other material, it is not completely impenetrable.

  8. CR-39 - Wikipedia

    en.wikipedia.org/wiki/CR-39

    A wide range of colors can be achieved by dyeing of the surface or the bulk of the material. CR-39 is also resistant to most solvents and other chemicals, gamma radiation, aging, and to material fatigue. It can withstand the small hot sparks from welding, something glass cannot do. It can be used continuously in temperatures up to 100 °C and ...

  9. Abbe number - Wikipedia

    en.wikipedia.org/wiki/Abbe_number

    Values of range from below 25 for very dense flint glasses, around 34 for polycarbonate plastics, up to 65 for common crown glasses, and 75 to 85 for some fluorite and phosphate crown glasses. Most of the human eye's wavelength sensitivity curve, shown here, is bracketed by the Abbe number reference wavelengths of 486.1 nm (blue) and 656.3 nm (red)