When you purchase a pair of sport sunglasses, which sunglass lens characteristics are most important to you? There are several factors that affect the quality of sunglass lenses that you wear to protect your eyes. The most important of course is that your eyes are protected from UV (ultraviolet) light. Over time, UV rays will destroy your eyes and cause cataracts to develop.
Secondly, you want the correct darkness factor as well as the right color. If a sunglass lens is too dark, you’re not seeing everything you need to see. If it’s too light, the sun’s brightness will stop you in your tracks. The volume of light transmission (VLT) is less in a dark lens and more in a lighter lens. 18 – 27% VLT is a good range for most sunny-day uses. Night time eye protection would demand a lens with 95 – 100% VLT. A gray, or smoke-colored sunglass lens gives the most natural color perception. A yellow sunglass lens protects your eyes from “blue light,” the most damaging of light in the color spectrum. For bright light situations, a copper colored lens with about 27% VLT delivers the highest resolution, blue-light-blocking sun protection for most daytime activities. Sometimes called a “driver’s lens,” this is a superior lens for golf or mountain biking as well.
Thirdly, you want a distortion-free lens, for the obvious reasons of being able to see well without optical distraction. Nothing is more irritating than buying a decent looking pair of sport sunglasses just to discover down the road those annoying bits of distortion in your vision. Cheap acrylic sunglass lenses can do that. Poorly made polarized sunglass lenses are worse. They will have flashes of color or blind spots moving in and out of the optical field. Except for fishermen, most sports enthusiasts may prefer a non-polarized lens. Bicyclists and motorcyclists in particular can experience blind spots on the road that disguise black ice and other obstacles, when they are wearing cheaper polarized eyewear. Sometimes a motorcycle windshield is already polarized, and adding polarized sunglasses on top of that simply blocks out the entire optical field through the windshield. Not good, yes?
Also, keep in mind that a lightweight sport sunglass lens is much more comfortable to wear. Ground glass lenses have excellent optical quality, but are very heavy and usually expensive. And if you engage in any type of activity that puts the lens in harms way, shatter-resistance is very important. The faster youâEUR(TM)re moving, the more critical this becomes. On the highway, the tiniest speck of sand becomes a high-speed projectile that can destroy cheap thin plastic or the eye behind it.
Furthermore, a shield-type lens, particularly a spherical, decentered lens, will give you a wide open optical field with optimum clarity for superior vision. A decentered lens has a similar spherical curve on the outside of the lens, as it does on the inside. This makes the lens thickest in the middle, and thinner at the edges. This, in part, helps with making a lens distortion-free. Obviously, a meticulously crafted production mold is critical in making a lens that is free from distortion or noticeable defects.
A close-fitting, spherical, single lens will hug your face best, provide ample eye lash room, have no annoying optical field-blocking frame, and will block wind most effectively. A comfortable frame that fits your head correctly without pinching completes the package.
All of these sunglass lens issues can be addressed by using a blue-light-blocking, polycarbonate, wraparound, spherical lens that fits closely to the face. For the best in eye protection, this lightweight, optically superior lens is the best way to proceed in active sports such as mountain biking, road biking, motorcycling, golfing, or even running. Any outdoor sport or activity will benefit from such a lens. Drivers (OTR – over the road – or otherwise) will also enjoy a lightweight blue-blocking decentered lens for sustained comfort and maximum optical acuteness.
High performance athletes demand the very best of themselves, as well as the equipment and gear that they use. Your eyes should have the finest eyewear, to not only protect your precious eyes, but to give you the most acute vision. We recommend using a pair of quality sport sunglasses.