Polycarbonate Lenses: Lightweight comfort. UV protection. Impact resistant.
Polycarbonate lenses are up to 10 times more impact-resistant than plastic or glass lenses and they provide 100% protection from the sun’s harmful UV rays. They are also lightweight, adding to the comfort of your eyeglasses, sunglasses, and sports eyewear.
A Brief History of Polycarbonate
Originally designed for canopies covering cockpits in fighter planes, polycarbonate offered an impact-resistant, optically clear window. This enabled pilots a full-field of vision without compromising safety. In the 1970s, the popularity of polycarbonate soared–literally soared to outer space as it began being used for astronaut helmet visors and space shuttle windshields.
Clearly, polycarbonate is a most durable material. However, it wasn’t until the 1980s that polycarbonate was introduced to consumers as a safe, affordable alternative to standard plastic or glass eyewear. Today, polycarbonate lenses set the standard in eyewear safety. These lenses are a smart choice for people active in sports, those who work in hazardous job environments, and especially for children.
Because of its durability, polycarbonate lenses are also ideal for people who prefer rimless eyewear designs because they are less likely to fracture than plastic or glass lenses. Those with a blind or lazy eye often utilize polycarbonate lenses, too.
What Makes Polycarbonate the Safest Lens Choice?
Polycarbonate lenses are the most impact-resistant lenses on the market because of its manufacturing process. The majority of other plastic lenses utilize a cast molding process. This is when a liquid plastic material is baked for long periods, in lens form, until the liquid plastic solidifies into a lens.
On the other hand, polycarbonate is a thermoplastic material produced from small pellets. Therefore, the earliest phase of polycarbonate lenses begin from a solid source, eliminating the cast molding process and instead use a process called injection molding in which the pellets are heated to a melting point. Once in liquid form, the polycarbonate is rapidly injected into lens molds. At this phase in the process, the lens molds are compressed under high pressure and cooled to form a final lens product–in a matter of minutes.
The difference in the manufacturing process is what makes polycarbonate a stronger, more impact-resistant lens.
Make the Most of Your Polycarbonate Lenses
To make the most out of polycarbonate lenses, seriously consider these other complimentary products:
Scratch Resistant Coating: Polycarbonate is an impressive impact resistant lens. However, part of the reason it’s so strong is because it’s, ironically, a relatively ‘soft’ material. Being flexible is what enables it to absorb energy without fracturing. But being a soft material requires a scratch-resistant coating to prevent surface scratches. Once a scratch-resistant coating is applied, your polycarbonate lenses will be nearly as hard as glass–yet remain highly impact-resistant.
Proper Frames: To ensure the safest eyewear at work and during sporting activities, frames specifically designed for safety are more than strongly recommended; putting polycarbonate lenses into frames not rated for use as safety glasses can actually be detrimental and dangerous. Your eyecare professional can advise you which frames are safety-rated and best suited for your lifestyle – at work and at home.
Because kids have a greater tendency to drop their glasses and play rough even when not actively participating in sports, all children’s frames should have polycarbonate lenses.
source : www.vsp.com