You are in the market for a new pair of sunglasses. Your spouse tells you to get polarized sunglasses while a co-worker says you really need mirrored lenses. Both argue that their choice is better than other kinds of shades. But are they telling the truth? Do polarized or mirrored lenses make sunglasses better?
The answer to that depends solely on how you define ‘better’. In the end, the answer boils down to your particular preferences. Figuring it out is a simple matter of understanding what polarized and mirrored lenses do and how they relate to UV protection.
Blocking UV Rays is Most Important
Ask 100 optometrists to describe the most important characteristics of a good pair of sunglasses and nearly all of them will mention UV protection. Blocking UV rays is the most important job sunglasses perform. If your glasses are not blocking UV rays, they are not doing you much good.
Olympic Eyewear, a Salt Lake City company that designs and distributes wholesale designer-like sunglasses, explains that UV protection is completely separate from polarization and mirrored lenses. Protection is achieved by a special layer embedded in eyewear lenses. That layer does not add any tint or reflective surface to the lenses.
The layer is essentially a filter that blocks out light waves of a certain frequency. As such, you could have a pair of lenses that offers 100% UV protection and still be completely clear. And for the record, sunglasses rated UV 400 protect against 100% of the UV rays your eyes would otherwise be exposed to.
Polarization Reduces Glare
With the basics of UV protection out of the way, let us move on to polarized lenses. The main function of polarized lenses is to reduce glare. This is accomplished by filtering light moving in a specific direction. Lenses can filter horizontally, vertically, or diagonally.
Sunlight reflecting off a body of water creates glare. That’s because the light waves disperse in multiple directions as they bounce off the water. Filter out some of those light waves and you eliminate glare. That’s what polarized lenses do.
A pair of polarized lenses have the same effect with your mobile phone. If you cannot read your phone in a vertical position while wearing sunglasses, turn it on its side. You should now be able see it just fine. That’s because both your sunglasses and your phone screen are polarized. If they are polarized in the same direction, they cancel one another out.
Mirrored Lenses Are Just for Style
Moving on to mirrored lenses, Olympic Eyewear says they are nothing more than a style choice. They do not offer any UV protection or anti-polarization capabilities in and of themselves. If you like mirrored lenses because you think they look cool, that’s great. But do not expect them to offer any additional UV protection or reduce glare.
Unlike UV protection embedded within a set of lenses, the mirrored look is achieved by adding a coating to the outside surface. This coating is so highly reflective that it reflects light just like a mirror. But its reflective capabilities are only one-way. You can still see through the lenses from the other side.
Perhaps you’re wondering if it’s possible for a pair of sunglasses to both be mirrored and offer appropriate UV protection and polarization. In short, yes. A pair of sunglasses can offer all three capabilities. It’s just that each one is achieved separately.
So, do polarized or mirrored lenses make sunglasses better? That’s up to you to decide. Just know that UV protection is what it’s all about at the end of the day.