What is The Difference Between 100% UV Protection and Polarized Sunglasses?

When we get a sunburn, it’s the ultraviolet light that causes the burn, so it’s no secret that ultraviolet rays can be harmful. It’s also no secret that too much exposure to ultraviolet light over time can cause changes in the skin and even skin cancer. Did you know that ultraviolet light can also affect your eyes? Studies have shown that prolonged exposure to UV rays can lead to:

• Cancerous changes to the skin on the eyelids


• Benign changes on the surface of the eyes, like Pingueculae and Pterygium


• A type of corneal sunburn called Solar Keratitis


• Cataracts


• Macular degeneration


• Cancers inside the eye like Choroidal Melanoma

Now that summer is upon us, we’re all spending more time outdoors, so it’s good to remember that the eyes need protection from UV light. Since Ultraviolet light exposure is almost always greater at higher altitudes, and since Calgary is at a moderately high altitude (1,048 meters, or 3,438 feet), it’s even more important where we live. Calgary enjoys an average of 333 days of sunshine each year, totalling 2396 hours. That’s a lot of sunshine to make us feel light sensitive!

UV Blocking Sunglasses Protect from all harmful Ultraviolet rays

Light sensitivity comes from two sources: UV exposure and Glare. Since there are negative health effects from Ultraviolet light exposure, all sunglasses sold in Canada must be UV blocking, by law. That’s not necessarily true at the swap meet on your tropical holiday though. UV Protection is part of every pair of Sunglasses purchased at Doig Optometry. We can also ensure that your clear eyeglasses are UV blocking.

Expert Tip: A common misconception about sunglasses is that they should only be worn in the sun, but it’s equally as important to wear sunglasses in the shade as UV rays reflected from other surfaces are dangerous.


Polarized Sunglasses Eliminate Glare

All light travels in a spiral, including visible light. Initially, all the light is spiralling in the same direction, but when it strikes a surface, the light spirals in the opposite direction when it reflects back. This mixed-light gives a confusing message to the visual system that we perceive as Glare.

Polarized lenses allow only the normal light to pass through, and not the light spiralling in the opposite direction. This minimizes the experience of glare. This is very soothing for the eyes and allows the wearer to see past the reflections on the surface of the water, or on a windshield for example. For this obvious reason, Polarized Lenses are very popular among drivers, boaters, and anglers.

Expert Tip: Digital screens emit polarized light, so Polarized Sunglasses block out parts of the image and are not ideal for digital devices. Also, Polarized Lenses eliminate reflections from the surface of a puddle on the road, creating a risk for motorcyclists and cyclists. Elite golfers who judge the lay of the green by the reflection of the surface of the blades of grass will notice that this is more difficult wearing Polarized Lenses that eliminate these reflections.



Since there’s no negative health effect from Glare, there’s no legal requirement that your sunglasses eliminate Glare. Patients who still experience light sensitivity in their UV blocking sunglasses sometimes think that their sunglasses aren’t dark enough. However, it’s more likely that the remaining light sensitivity is actually Glare Sensitivity, which can be eliminated with a quality pair of Polarized Sunglass Lenses.

Key Takeaways

UV Blocking Sunglasses protect your eyes from dangerous ultraviolet rays and are crucial to good eye health. Polarized Sunglass Lenses can make your eyes more comfortable by eliminated glare. To find the right sunglasses for you, call Doig Optometry today for a consultation. Whether you are deciding between simple UV blocking sunglasses or Polarized Sunglasses, one of our friendly and helpful team members will help you find the best lenses for you. See Sharp, Look Sharp, Love Your Glasses®!

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