Getting the right lenses and coating for your vision, fashion and eye protection needs is a complicated business. Fortunately for you, it’s OUR business to help you select lenses and coatings that fit your prescription, budget and lifestyle. Here’s a little info can help you understand your lens choices, and separate the gimmicks from the goods.
Basically, there are 5 types of materials that we make glasses with out there:
All eyeglass lenses must meet federal standards; some shops require theirs to pass even higher optical hurdles.
The future’s plastic, and there are four types:
The standard lens used for prescriptions that aren’t too strong, plus or minus 3 and lower. (CR stands for “Columbia resin,” the material used for airplane windshields during World War II; 39 refers to the recipe number.) CRs usually cost about $89 to $119 for single-vision lenses, not including coatings that can add another $50 or so the total (we’ll get to coatings in a minute).
When you get into the “blind as a bat” category, higher than plus or minus 4, it’s time think about trading up to high-index lenses. (How in the world do eyeglasses work, and what do all these numbers mean? Find out.)
High-index lenses are made from a denser material than CRs, so they’re thinner and lighter. Not all high-index lenses are the same, though. Lenses with higher indexes of refraction (IORs) bend light more efficiently; the higher the IOR, the thinner the lenses and the steeper the price. High-index lenses cost about $70-$150 more than CRs depending on just how thin you want them.
Lenses made with Trivex are ultra-light; it blends
the benefits of lightness and thinness, often resembling the thinness
of a high index lens, but weighing even less than polycarbonate.
Trivex material also provides high impact resistance as well as blocking 100% of the sun’s harmful UV
rays. And it’s an excellent choice for
rimless (or drill-mount) frames and lightweight fashion frames.
The lens of choice for kids and athletes because it’s the most impact-resistant (it’s the same stuff used in bulletproof glass) and also has a high IOR, but not the best visual properties (???? Go figure – we put kids in a lenses that’s safe but has the worst optics of all materials??). State law requires us to sell ***ONLY*** polycarbonate to kids under 18.
A tip: Because the material is so flexible and soft, it is therefore highly scratchable; no coatings will really help reduce that issue. You can skip the UV protective coating too, since the material has built-in ultra-violet protection. With these lightweight, slim lenses, which are priced in the same ballpark as high-indexes, you’re primarily paying for the extra durability.
The downside of polys is that they have a lot more distortion than other thin lens options. So unless you spend more time on the basketball court than in your car, go with high index.