Last updated on June 6th, 2017 at 05:52 pm
Both polycarbonate and Trivex lenses are thinner and lighter than routine plastic lenses. They also offer 100 percent security from the sun’s hazardous UV light and are up to 10 times more impact-resistant than plastic or glass lenses.
This combination of light-weight comfort, UV protection and impact resistance also makes these lenses an excellent option for children’s glasses and safety glasses.
Polycarbonate was developed in the 1970s for aerospace applications, and is currently used for the helmet visors of astronauts and for space shuttle bus windshields. Eyeglass lenses made of polycarbonate were presented in the early 1980s in response to a demand for lightweight, impact-resistant lenses.
Ever since, polycarbonate lenses have become the requirement for shatterproof glass, sports safety glasses and children’s eyeglasses. Due to the fact that they are less likely to fracture than regular plastic lenses, polycarbonate lenses also are a great choice for rimless glasses styles where the lenses are attached to the frame components with drill mountings.
Many other plastic lenses are made from a cast molding procedure, where a liquid plastic product is baked for long periods in lens kinds, solidifying the liquid plastic to produce a lens.
But polycarbonate is a thermoplastic that starts as a solid material in the form of little pellets. In a lens production process called injection molding, the pellets are heated till they melt. The liquid polycarbonate is then rapidly injected into lens molds, compressed under high pressure and cooled to form a finished lens product in a matter of minutes.
In spite of its numerous advantages, polycarbonate isn’t really the only lens product appropriate for safety applications and children’s eyewear.
In 2001, PPG Industries (Pittsburgh, Penn.) presented a rival lens product called Trivex. Like polycarbonate lenses, lenses made of Trivex are thin, lightweight and much more impact-resistant than routine plastic or glass lenses.
Trivex lenses, however, are composed of a urethane-based monomer and are made from a cast molding process similar to how routine plastic lenses are made. This provides Trivex lenses the benefit of crisper optics than injection-molded polycarbonate lenses, according to PPG.
Polycarbonate vs. Trivex Lenses: A Quick Comparison
Here is a quick comparison of polycarbonate and Trivex lenses to assist you choose which lenses might be best for you:
- Density. Polycarbonate has a higher index of refraction than Trivex (1.58 vs. 1.53), so polycarbonate lenses are about 10 percent thinner than Trivex lenses.
- Weight. Trivex has a lower specific gravity than polycarbonate, making Trivex lenses about 10 percent lighter than polycarbonate lenses.
- Optical clearness (main). Trivex lenses have less internal stress and might produce sharper central vision than polycarbonate lenses.
- Optical clearness (peripheral). Trivex lenses have a greater Abbe value and may produce sharper peripheral vision with less chromatic aberration than polycarbonate lenses.
- Impact resistance. Polycarbonate and Trivex lenses have comparable impact resistance.
- UV security. Polycarbonate and Trivex lenses both block 100 percent of the sun’s UV rays without the requirement for unique UV-blocking lens finishes.
- Availability. Polycarbonate lenses are available in a larger range of lens styles (e.g., progressive lenses and other multifocals) than Trivex lenses.
- Cost. The cost of polycarbonate and Trivex lenses can differ significantly, however numerous optical stores charge more for Trivex lenses than polycarbonate lenses.
Your professional optician can go over the pros and cons of polycarbonate and Trivex lenses so you can choose which lens material is the best option for your requirements and budget.
Polycarbonate and Trivex lenses are much more impact-resistant than routine glass and plastic lenses (consisting of other high-index lenses) because these lightweight lens products are relatively “soft” — which indicates they can absorb energy without lens fracturing.
This versatility also means polycarbonate and Trivex lenses need a scratch-resistant coating to avoid surface scratches. Today’s contemporary scratch-resistant coverings can make the surface of polycarbonate and Trivex lenses nearly as hard as glass.
A lot of eye care experts provide a lens warranty to safeguard your lenses versus scratches for a specific duration of normal use. Ask your optician for details.
Appropriate Frames For Polycarbonate And Trivex Lenses
When it comes to eye safety, polycarbonate and Trivex glasses lenses are just part of the option.
For the best eye defense at work and during sports, make certain you likewise purchase high-quality safety frames or frames designed particularly for sport eyeglasses.
Standard glasses frames are not ranked for use as safety glasses and typically don’t supply the type of eye protection needed for sports. For that reason, playing sports while using a glasses frame that is not rated for sports eyewear threatens and can result in a severe eye injury if the frame breaks, dislodging the lenses.
If you require safety glasses, seek advice from an optician who can inform you which frames are safety ranked.
For children’s eyeglasses, select a sturdy frame and lightweight polycarbonate or Trivex lenses. Even if she or he does not participate in arranged sports, choosing impact-resistant eyeglass lenses and frames is an essential action to safeguard your child’s eyes throughout the day for a life time of great vision.