• 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
• 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 raysLight 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 GlareAll 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.