What Are Polarized Sunglasses?
Polarized sunglasses have lenses that reduce glare when sunlight reflects off materials like glass, water, and snow. Polarization can be helpful in certain activities like playing outdoor sports or spending time on the water, and it can be crucial in situations where there are hazards that must be seen and avoided, such as when driving in bright light on snowy roads.
This article explains how polarized sunglasses differ from others and their advantages and disadvantages.
How Polarized Sunglasses Work
Glare occurs when light beams reflect off surfaces and are scattered horizontally in front of you. Light hitting the eyes this way can overwhelm their photoreceptors — rods that enable vision in darker conditions and cones that allow you to see colors.
When that occurs, you can experience a partial or complete visual “whiteout.” Your natural reaction to glare is to squint, which helps minimize it. However, that tactic is only partly effective, and you can experience other problems like tension headaches from squinting for too long.
Polarized lenses have a chemical applied in a vertical pattern that offsets the horizontal light to a degree, reducing the glare you perceive. This chemical may coat the lens surface (in less expensive sunglasses) or be added between two layers of lens material in higher-cost versions. Non-prescription and prescription lenses can be polarized, and higher-quality sunglasses are almost always polarized.
Polarization can also be used in other optics, like camera lenses made for nature photography.
Are Polarized Sunglasses Better?
It wouldn’t be accurate to say that polarized sunglasses are better. However, they can be beneficial in certain situations. The glare reduction provided by polarized sunglasses can be helpful when driving, boating, fishing, or playing outdoor sports.
Polarized sunglasses can also reduce eye strain and fatigue, create greater light/dark contrast, and enable you to see colors more accurately. You can get polarized lenses in different colors for different purposes.
For example, pale orange or yellow lenses are good for driving at night, blue lenses can reduce eye strain for people who work at a computer, and dark polarized sunglasses can be beneficial in especially bright conditions, like when fishing on a sunny day. The darkness of a polarized lens doesn’t affect how it handles glare.
There are some drawbacks to polarized sunglasses, including:
- Distortion with digital devices. Some digital screens may appear distorted when viewed through polarized lenses. This includes devices with liquid crystal displays (LCDs).
- Dimming of images at night. Even polarized lenses for nighttime driving reduce the amount of light entering the eye and can hurt visibility.
- Visual changes. Some people report that polarized lenses cause their vision to be blurred or “highly 3-D,” affecting depth perception.
Polarized lenses also may be inappropriate for certain activities. For example, while the snow on a ski slope can create glare, skiers and snowboarders are advised not to use polarized sunglasses or goggles as they can make it harder to judge terrain.
As a result of these potential issues, it’s a good idea to ease into using polarized sunglasses.
Polarized Sunglasses and UV Rays
While sunglasses can offer both polarization and UV protection, polarization itself doesn’t protect your eyes from ultraviolet (UV) light. This is crucial since long-term exposure to UV rays can cause health problems like macular degeneration and eye-related cancers. Be sure to understand the protection provided before purchasing sunglasses.