But are they better for your eyes than regular sunglasses?

Think of polarized lenses as a tool for fine-tuning for your vision while wearing sunglasses. They are especially useful if you are an avid outdoorsman, an active athlete, or find yourself in high-glare situations.
 
Before we dig into the benefits of polarized lenses, let’s step back for a minute and focus on the most important reason for wearing sunglass—UV protection. 

UV rays can be just as harmful to the eyes as they are to the skin. For that reason, it’s very important to select sunglasses that have this protection.
 
But what about polarized lenses? Are they even safer? Not exactly. 

While they do sharpen your vision in situations where glare can be distracting or even dangerous, they don’t offer any additional protection from UV light. So in other words, they’re not healthier for your eyes, but they do improve your vision for many outdoor activities.

How Polarized Lenses Work

Brought to You by NASA

Polarized lenses were actually a brainchild of NASA Jet Propulsion Laboratory scientists who studied eagles’ eyes to uncover clues about their exceptionally sharp vision. 

What they found is that a naturally occurring oil in an eagle’s eye controls certain properties of light, scattering and limiting certain wavelengths. 

Scattering, which you have experienced when light bounces off the surface of a lake, can really keep you from seeing things both above and below the surface. Eagles rely on the oil to overcome these challenges and maintain razor sharp vision.

Sharpen Your Vision in High-glare Situations

Scientists adapted this discovery to create special polarized filters that are applied to sunglass lenses. These filters absorb light reflected or scattered from horizontal surfaces. We call this glare and it can impede our vision especially in dangerous or fast moving situations. 

Polarized glasses come in handy in high glare situations such as light reflecting off of roads, cars, or water.

So when you are picking out sunglasses, the first thing you should check for is UV protection. But if you drive, are active in sports, or often find yourself on or near the water, you may want to pick sunglasses with polarized lenses also to give you the sharpest vision possible.

Insider tip: Want to be sure you are getting what you paid for? Sunglasses may be labeled polarized, but there is one way you can tell for sure. Polarized lenses block those scattering waves of light specifically from horizontal surfaces. Hold your lenses up to something reflective like the hood of a car and slowly tilt your glasses. As the angle of the lens changes, the amount of glare the lenses lets through should also change.