What Are Polarized Sunglasses? Benefits, How They Work & More

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Polarized sunglass lenses feature a specialized filter within the lens that significantly reduces glare more effectively than standard sunglasses. This glare-reducing capability renders polarized lenses an ideal choice for activities where reflective glare poses a problem, such as driving, boating, and fishing.

How They Work: The History and Physics Behind Polarized Lenses

Sunlight scatters in all directions, but when it hits a flat surface, the light that is reflected becomes partially polarized—meaning the light rays align in a more uniform direction. 

Edwin Land, a Harvard University freshman in 1929, innovated by embedding tiny crystalline materials in a thin, transparent plastic film to create polarized light, which he patented as the “J sheet,” later known as Polaroid. The Polaroid Corporation, established by Land in 1937 in Boston, gave rise to the term “Polaroid” used to describe polarized lenses, though it’s sometimes inaccurately applied to similar products by other manufacturers.

Land’s polarizing film was designed to selectively block light rays traveling in one direction while allowing others to pass through, making it exceptionally effective in filtering reflected light. 

Originally intended for automotive headlamps to reduce glare for drivers, the application shifted to sunglasses after a colleague of Land’s discovered its effectiveness in reducing water surface glare, enhancing visibility for fishing and subsequently for various outdoor activities.

Now, polarized filters have expanded their use beyond sunglasses to include camera lens filters and computer monitor anti-glare screens.

How to Know if Sunglass Lenses Are Polarized

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Although polarized lenses appear identical to regular sunglasses, a simple test can reveal their polarization:

  1. Locate a flat, reflective surface.
  2. View the reflection through the sunglasses a few inches from your face.
  3. Rotate the sunglasses 90 degrees. If the glare reduces through one lens orientation but not the other, the lenses are polarized. With non-polarized lenses, the reflection’s intensity will not change with the rotation of the glasses.

When Are Polarized Sunglass Lenses the Best Choice?

Polarized sunglasses excel in environments where reducing glare can enhance safety and comfort:

  • Boating – They allow better visibility of underwater hazards by cutting down surface glare.
  • Fishing – Enables clearer visibility beneath the water’s surface.
  • Driving – Reduces glare from the vehicle’s dashboard, hood, and reflective surfaces on other vehicles.
  • Beach Activities – Minimizes eyestrain from sand and water reflections.
  • Skiing – Cuts down glare from snowy surfaces, enhancing slope visibility.

When May Polarized Lenses Pose a Problem?

Despite their benefits, polarized lenses might not be the best choice in certain scenarios:

  • Icy Conditions – Polarized lenses might make icy patches on slopes harder to distinguish.
  • Polarized Windshields – Interference patterns could appear if your car’s windshield is polarized.
  • LCD Screens – Displays on devices like ATMs might be more challenging to read through polarized lenses.

Conclusion

Polarized sunglass lenses offer unparalleled advantages in combating glare across various activities, enhancing visual clarity and reducing eye strain. However, their specific characteristics may not suit every situation. Understanding when and where to use polarized lenses can significantly improve your outdoor experiences, safeguarding your eyes while maximizing visibility and comfort.