Polarized vs Non-Polarized Sunglasses

If you’re shopping for a new pair of sunglasses, you may wonder whether to pick polarized or non-polarized lenses. Both options preserve your eye health by blocking the sun's harmful ultraviolet (UV) rays.^1,6

polarized sunglasses on sunny sky uv protection

There are a few key differences between polarized and non-polarized lenses. The main difference is that polarized lenses reduce glare from bright sunlight and reflective surfaces.

Read through to learn when you might want to wear polarized shades and when a non-polarized option would be a safer choice.

What Are Polarized Sunglasses?

Polarized glasses are a type of sunglasses that protect your eyes from harsh light that reflects off flat surfaces.

Also called anti-glare sunglasses, polarized lenses offer visual clarity in various conditions, including:

Daytime driving on the highway or asphalt
Fishing and boating
Skiing and other snow sports
Golfing

Usually, light scatters when it bounces off an object’s uneven surface. But if the surface of an object is smooth, the light will vibrate in one direction (horizontally) into your eyes.

That strong glare can be painful and even harmful to your eyes. Polarized sunglasses, however, reduce the reflection to protect your eyes.

How Do Polarized Lenses Work?

Polarized lenses have a special chemical applied to them that filters light. The molecules line up vertically, which blocks out the horizontal rays of light that cause glare.

Because the filter on polarized sunglasses is vertical, and glare is typically horizontal light, only some light can make it through each lens. Normal amounts of light can still pass through the lens, but the near-blinding brightness of glare doesn’t.

Polarized vs. Non-Polarized Sunglasses

Polarized and non-polarized sunglasses both offer protection from light.

The primary difference is:

Non-polarized lenses reduce the overall intensity of light by treating all light equally. Sparkles, shimmers, and glare may still bother your eyes in certain conditions, like snow or water.
Polarized lenses have a special chemical that blocks out bright light that reflects off of smooth surfaces. They also reduce ambient light, like non-polarized lenses.

Both sunglasses protect your eyes from harmful light on a sunny day. But only polarized lenses counteract bright surface glare.

To ensure protection from UV damage, look for a pair of sunnies that blocks 99% or 100% of UV light.

Why Buy Polarized Sunglasses Over Non-Polarized Sunglasses?

You should purchase a pair of polarized sunglasses over non-polarized sunglasses if you spend a lot of time on the road or by the water. Polarized lenses will help to deflect bright glares from surfaces like asphalt and calm water.

Other benefits of polarized lenses include:

Reduces glare and the amount of light that reaches your eyes
Less eye strain may lead to reduced tiredness
Images appear crisper and clearer

When is it Better to Use Polarized Lenses?

Polarized lenses help to reduce glare from highly reflective surfaces.

Wear polarized glasses when you are:

Driving in daylight
Biking
Jogging
Fishing
Boating
Skiing in snowy conditions

When are Non-Polarized Lenses Better?

Polarized lenses can make it difficult to read LCD screens, such as the display on your car dashboard. Pilots are advised to wear non-polarized glasses while flying to avoid potential danger when using the plane’s control panel.⁵

You may opt for non-polarized sunglasses if you’re reading text from an LCD screen, such as an ATM or smartphone.

Other situations where you should wear non-polarized sunglasses include:

Operating heavy machinery
Driving in low-light situations
Reading
Skiing in icy conditions (polarized sunglasses may make patches of ice less noticeable, which can be dangerous for skiers)
Using digital screens

Driving at night in polarized glasses can be dangerous and is not recommended.³

Click here for more information on the best types of sunglasses for your face shape.

Summary

Polarized and non-polarized sunglasses protect your eyes by reducing ambient light.
Polarized lenses take your visual experience a step further by offering glare protection.
When light reflects off smooth surfaces, it aligns in a single, horizontal direction and causes glare.
The chemical on polarized lenses reduces glare by counteracting horizontal light.
Polarized lenses can help you see better in certain situations, like highway driving during the day and outdoor sports.
Non-polarized lenses may be a better choice while driving at night, viewing digital screens, and skiing in icy conditions.

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