Eyewear guide
Polarized Sunglasses: How They Work and When to Choose Them
Polarized lenses cut the bright, reflected glare that bounces off water, wet pavement and car hoods. Here's how they work, where they help most and when you might skip them.
What polarization does
Ordinary sunlight vibrates in every direction. When it bounces off a flat, shiny surface like water, a wet road or the hood of a car, much of the reflected light ends up vibrating in one direction, mostly horizontal. That's the harsh, white glare that washes out whatever is underneath.
A polarized lens contains a filter oriented vertically. It blocks much of that horizontal glare while letting other light through. The result is less glare and a clearer view of the surface itself, like looking into the water instead of at a sheet of reflection.
Polarized lenses still come in ordinary tints and darknesses. The filter works quietly in the background, so a polarized gray lens looks much like a regular gray lens until you hold it up near water or a wet road.
Where polarized lenses help most
Polarization is most useful anywhere there's reflected glare from flat surfaces.
- Driving: less glare off wet roads and other cars, and less of your dashboard reflected in the windshield.
- Boating and paddling: less shine off the water's surface.
- Fishing: anglers like being able to see past the surface glare into the water.
- Beach days: less glare off wet sand and waves.
- Snow: less glare off bright, flat snow, though some skiers prefer non-polarized lenses, as explained below.
On cloudy days or in shade, there's less reflected glare to filter, so the difference is smaller. On a bright day by the water, it's easy to notice.
The trade-offs
Polarized lenses are a great default for many people, but they aren't the best choice for everything.
- Screens: many LCD screens, including some phones, car dashboards, gas pumps and ATMs, use polarizing filters of their own. Through polarized lenses they can look dim, black or rainbow-patterned at certain angles.
- Pilots: many pilots prefer non-polarized lenses because polarization can make cockpit displays harder to read.
- Skiing and snowboarding: some skiers prefer non-polarized lenses because the shine off ice is a useful cue that a patch is icy.
- Car windows: some car windows show faint patterns through polarized lenses, an effect of how the glass is made.
If your car relies on a screen-heavy dashboard, try polarized lenses behind the wheel before you commit, or keep a non-polarized pair for driving.
How to test a pair, and what polarization doesn't do
Two quick tests
- The screen test: look at a phone or computer screen through the lens, then slowly rotate the sunglasses 90 degrees. If the screen dims or goes dark at some angle, the lens is polarized.
- The two-pair test: hold two pairs of sunglasses so one lens overlaps the other, then rotate one pair 90 degrees. If both are polarized, the overlap goes very dark.
Polarized is not the same as UV protection
Polarization handles glare. UV protection is a separate feature, and a polarized lens isn't automatically UV-blocking. The two work independently, so a lens can have one without the other. Many sunglasses offer both, but the label is the only way to know, so look for 100% UV protection or UV400.
Compare polarized and non-polarized with our team
Aesthetic Eye Care in San Luis Obispo offers prescription and non-prescription sunglasses, including polarized lenses, all with 100% UV protection. Our opticians can help you weigh polarized against non-polarized for the way you drive, fish or spend time outdoors.
Bring the phone you use for navigation or photos, so you can see how its screen looks through polarized lenses before you decide. Call (805) 439-1010 or request an appointment online.
Are polarized sunglasses worth it?
If you spend time near water, drive a lot in bright conditions or dislike glare off wet roads, most people find them worth it. If you rely on LCD screens outdoors, try a pair first.
Can I get polarized prescription sunglasses?
Yes. Polarized lenses are widely available in prescription sunglasses. Your optician can tell you which lens options suit your prescription and frame.
Do polarized lenses come in different colors?
Yes. Gray and brown are the most common, and green, rose and mirror-coated polarized lenses are available too. The polarizing filter is separate from the tint color.
Why does my phone look black through my sunglasses?
Your phone's screen gives off polarized light, and your polarized lenses block it at that angle. Turn the phone or tilt your head and the screen usually reappears.
Keep reading
More from our eyewear guide
Sunglass Lens Colors: What Each Tint Does
Gray, brown, green, rose, yellow and more, plus light categories and how to match tint to activity.
Read about sunglass lens colorsSunglasses for Central Coast Life: A Pair for Every Plan
Matching frames and lenses to beach days, paddling, trails, cycling, driving and foggy mornings.
Read about sunglasses for coastal lifePrescription Sunglasses Options: Pros and Cons of Each
Prescription sunglasses, clip-ons, light-adaptive lenses and more, with the pros and cons of each.
Read about prescription sunglasses optionsAccepting new patients
Make an appointment with our team
Reach out to Aesthetic Eye Care for your initial appointment and experience quality eye care in San Luis Obispo.