Everything You Need to Know About Polarized Sunglasses

When buying new sunglasses, you may ask: Do I really need polarized lenses? As you should! Polarization isn’t free. A classic pair of Wayfarers with polarized lenses ($203) lists over 30 percent more than the non-polarized version ($153). “The lenses look the same when you see them, but there are physical layers, not just coating layers, in these lenses that take a lot more time to make,” said Dave Barton, the founder of premium eyewear brand David Kind.

Polarized lenses immediately affect vision, reducing glare off of flat surfaces. But The quality of the material and method of manufacturing greatly affects both the price point and the optics. “A polarized lens in a $10 pair of glasses is going to have some of the properties of a polarized lens in a $500 pair of glasses,” Barton said. “But, you’re getting 30 percent more effectiveness and quality, and maybe 50 to 80 percent more durability when you start going up.”

There are many manufacturers making medium and low-end polarized lenses, but the highest quality glass comes from just a few factories across the world, including Barberini in Italy and Nakanishi in Japan. “When you’re sourcing your lenses, it makes a difference to a point what you’re picking,” Barton said.

To better understand how polarized lenses work, the range of available options and who benefits the most from polarization, we talked to few independent eyewear experts.

The Experts

Dave Barton, David Kind: Before starting David Kind, Barton ran product, first at Spy Optic, and then at Oliver Peoples, spending much of his time traveling between factories in Italy, Japan and Germany. Barton’s tenure at Oliver Peoples started just after the brand was acquired by Oakley.

Aaron Behle, SALT.: Before starting SALT. in 2013, Behle worked as the International Brand Manager for Oakley from ’96 to ’99 and as the Vice President and International Brand Manager for Reef from 2001 to 2005. From 2006 to 2010 he was the COO of Dragon Alliance. For the following three years, he was the Vice President of Skullcandy.

Tom Daly and Max Vallot, District Vision: Daly and Vallot founded District Vision in 2015. Steeped in the fashion world — Vallot worked at Saint Laurent and Daly worked at Acne — they came up with the idea of a fashion-inspired, athlete-focused sunglass brand and spent two years testing and developing prototypes.

Why are polarized lenses important?

Light is exhausting for your eyes. As beams bounce off different surfaces, and come in from different angles, your pupils struggle to keep up with moment-to-moment changes. Polarized lenses help make things easier on your eyes by “channeling” light and reducing its movement.

“Polarized lenses address eye fatigue and strain from reflected light”

“Channeled light provides more visual clarity and definition,” says Behle. “Polarized lenses also address eye fatigue and strain from reflected light. Eye fatigue is caused as your pupils chase reflected light, which causes constant expansion and contraction of the eye as it adjusts to the changing angle and intensity of the light. This eye fatigue is a direct trigger for headaches and migraines.”

Sunglasses help guard your eyes from the blinding light of the day, and polarized lenses go even further. “Polarized lenses are almost like mini Venetian blinds — there are microscopic blinds that are in the film in the lens,” says Barton. “That cuts out the glare that’s coming into your eyes at that angle. It’s very effective at this.”

What makes polarized lenses different from non-polarized lenses?

In short, they use an additional film to block additional light coming in at weird angles.

“Polarized lenses have a polarized film that filters reflected light in a vertical plane (the reflected light is predominately vibrating in a horizontal plane),” says Behle. “In channeling that light, polarized lenses remove the majority of electromagnetic vibration, also known as glare.”

SALT.

While all polarized lenses do the same thing, they accomplish it using different materials. “There are many different levels and many different price points. The basic way that it works is the same — it requires a film,” says Barton. “There are different quality levels of film where some are more effective than others, but the big difference comes in how the lens is made with that film and how clear the lens is.”

Are all polarized lenses made the same way?

No, there are a number of different ways, which use different materials and produce different results.

Cheap glasses generally use acrylic or acetate material with a polarized film in between. “They use heat to form it into the spherical shape of a lens, and then they cut the lens,” Barton explains. “Those are the cheapest, but they also have the most distortion of the lens. You can see these hot spots around the edge of the lens that cause distortion and reduce the polarize effectiveness. And they scratch really easily too.”

One step up is glasses with injection-molded polycarbonate lenses. “You see a lot of this being used. It’s what Oakley uses primarily, and it’s what most of the other sports brands use,” Barton says. “It’s an impact-resistant material, and it’s more scratch resistant than laminated lenses. The film is put into a mold and they inject the polycarbonate material around it. That makes for a good strong lens, but it’s not a clear lens to look through. It can distort the polarized film.”

One step up from there are polarized CR39 lenses. “Here, you have two wafers and you glue the polarized film in between the two wafers of the lens,” Barton explains. “Done with a high quality, this can be a much clearer lens than the polycarbonate one, but it’s not impact-resistant.”

And at the top of the list, in terms of optical clarity, is good ol’ glass. “Glass is primarily what we use at David Kind,” Barton says. “It’s done in the same construction method as the CR39, but it’s going to be the clearest, most scratch-resistant material. It seems to affect the polarization film the least. If it’s manufactured in a high-quality facility, it doesn’t distort the polarized film, so you have nice polarized effectiveness all around the periphery of the lens. “

What are the main differences between low-quality polarized lenses and high-quality polarized lenses?

The quality of polarized lenses comes down to two basic ingredients: the quality of the lens and the quality of the polarized film.

David Kind

“The highest quality lenses are optical-grade and they’re predominately made out of CR39 or mineral glass,” Behle explains. “The second component is the quality of the polarized film and how the film is adhered to the lens and aligned. Quality polarized lenses use a higher quality polarized film, sandwiched between the two lenses so that the film is perfectly aligned in the worn position.”

Higher-quality glasses will also add some extra bits of protection, says Behle. “They also use a backside anti-reflective coating on the inside of the lens that absorbs light that enters from the back of the lens and prevents this light from reflecting back into your eye. Further, high-quality lenses will use hydrophobic and oleophobic coatings that repel water and oils, to ensure that your lens is clean and clear.”

Can you get a good polarized lens at an entry-level price?

You aren’t going to get great polarized glasses for $10, but it doesn’t have to cost an arm and a leg either.

“One of the best values out there is a glass polarized Ray-Ban aviator,” Barton says. “That’s a great quality lens and they’ve been doing it for years. As you move up-market, you start getting into better frames, and you start getting things for the lens like anti-reflective coating, which make a huge difference. You can get into photochromics, you can get into mirror coatings — all of that increase the price as well.”

“Cheap, acrylic acetate ones from the gas station won’t last.”

If you cheap out, you’re going to be compromising on lens quality and durability. “When you go down-market, you start going into the polycarbonate materials,” Barton says. “The cheapest of the cheap are the gas station polarized ones are the acrylic acetate ones that won’t last.”

Do I really need polarized lenses?

Reasonable people can disagree! It’s a matter of personal preference.

“Everyone [should have polarized lenses,” says Behle. “It is absurd to be wearing a sunglass, especially a premium sunglass, that does not have a polarized lens. Beyond UV protection and reducing the amount of light that penetrates the lens, which virtually all sunglasses have, the real point of having a sunglass is being able to see clearly and without eye strain in the constant barrage of reflected light.”

Barton disagrees. “My experience is it’s definitely not for everyone,” he says. “It’s for most people, but it’s not for everyone. Some people feel a little discombobulated because they’re disoriented by the effects that polarized can have. They’re not used to it. For example, car window screens that have window tint, you start seeing these purple blotches. It can change how you perceive the road surface. If you’re a skier and you want to see the reflection of ice on a sunny day, you don’t want polarized. If you’re a pilot, many of the windscreens are polarized themselves, and when you combine a polarized windscreen and polarized glasses, it can black out the screen, so they don’t wear polarized.”

At the end of the day, however, it’s safe to err on the side of polarized lenses if you’re on the fence. “For most people, you’re going to have a better visual experience, especially when you’re in bright conditions, near water or outdoors,” Barton says.

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