Q: I was recently shopping for new glasses, but it seems there are lots of lens types available. How to choose?
A: I think most people would be surprised to learn how many options and choices there really are in ophthalmic lenses today! First, the best lens material is not glass anymore. Glass was the toughest in resisting scratches, but its tendency to break easily and the heaviness are serious drawbacks. The risk for serious eye damage or penetration if a lens breaks is extreme, so polymers have become the lens material of choice.
However, there are many polymers available. The most common is called CR-39, and is fine for general low prescription powers in regular full rim glasses. This means if your vision prescription is not too strong ( which can make your lenses thicker ), and the frame you choose has a rim that goes all the way around the lens ( not a rimless design ), CR-39 if likely fine. But for rimless frames, and higher prescriptions, special polymers like Trivex are stronger and thinner and lighter weight. Especially if your frame requires drilling tiny holes to mount the lenses with tiny screws, the risk of cracking or breakage is best reduced with Trivex.
Now, for lens treatments. Virtually everyone wants lenses to be scratch resistant. Optical labs can treat the lenses with a very tough, scratch resistant coating……but the type and strength of coatings varies quite a bit. Choosing without professional guidance is largely a guessing game.
We hear complaints about night driving and glaring headlights all the time, so most people prefer glare reducing lenses. These “anti-glare” lenses are made with another coating process using heat and high pressure. This can also add a day or two to the production time. Again, there are many levels or quality in glare free lenses. Generally, the better coatings cost more.
Lastly, everyone hears about “blue light” filters these days. These likely protect your eyes from potentially damaging wavelengths of light from computer screens, but the research is not conclusive about just how damaging this really is. Nonetheless, adding blue light filtering is popular, especially if you spend hours a day on screens for work or at home. More certain to cause damage is ultraviolet ( called UV ) radiation from the sun. We know UV can cause skin cancers in our eyelids, and accelerate cataract formation inside our eyes, and likely increase damage to our retinas in the back of our eyes. So simply put, everyone should have the best UV blocking available.
As you have likely gathered by now, choosing wisely the lens type and treatments you should have, or would prefer is confusing. Obviously, we recommend an ophthalmic professional to guide you in these choices. Best is your Optometric Physician or Optician to recommend lens choices for your eye health and lifestyle.
Yes, these choices can add cost to your glasses. Please recognize that more people will wear their glasses every day for 2-3 years! What else do you buy that you rely on for better appearance and eye health for the next 1000 days? Invest wisely in your eyewear.
