Polarized sunglass lenses help reduce glare caused by sunlight reflecting off surfaces like glass, snow, water, and pavement. They have long been recommended for outdoor sports enthusiasts, but truthfully, they’re a great option for almost anyone who ventures out on the open road.
They can also be a helpful solution to people with light sensitivity (photophobia), which can be caused by eye health issues such as migraines and keratitis. Patients who’ve undergone cataract surgery also struggle with light sensitivity.
How do polarized lenses reduce glare?
Whereas sunrays usually shine out fairly evenly in every direction, when they hit flat, reflective surfaces, the rays bounce off and polarize (i.e., focus in one generally horizontal direction). This magnifies the sun’s already bothersome glare and further disrupts outdoor vision.
Polarized lenses are reinforced with a chemical laminate — either on one side of the lens in less expensive versions or encased between layers of lens material in higher-quality sunglasses — that helps filter out the intensified sunlight. This polarized laminate filters the sunlight and reduces glare by eliminating horizontal rays that can’t pass through the vertical pattern of the laminate.
Because these lenses shield your eyes from this intensified glare, vision in otherwise compromised conditions becomes clear and precise — for instance, a fisherman who would otherwise see only the bright white shimmer across the surface of the lake, through polarized sunglasses will now clearly see all that lies beneath the surface of the water, barring any muddy or murky interference.
Are there any limitations with polarized sunglasses?
Polarized lenses are a revelation for many outdoor enthusiasts and long-distance drivers, but they’re not for everyone. Because of the way they shield reflected light, they’re not a good idea for downhill skiers, for example. These athletes need to be aware of icy conditions, which tend to reveal themselves as brighter, highly reflective patches in the snow.
These lenses also tend to cause difficulty reading some digital screens that use liquid crystal displays (LCD), like the screens at gas station pumps or ATMs. Phone screens and the displays on some instrument panels (e.g., in your car or a plane) also become challenging to read through polarized lenses. In these instances, it’s best to reconsider the use of polarized sunglasses as driving, flying, and even boating require split-second reaction time based on information provided in these screens.
More to consider before you buy polarized sunglasses
If you’re over 40 and spend a lot of time outdoors, whether for work or play, talk to your eye doctor about polarized progressive lenses, which might be best for your new sunglasses. There are also photochromic polarizing lenses, called Transitions Vantage, that are crystal clear indoors and then darken and polarize when the wearer steps into direct sunlight.
Your polarized sunglasses can be made even more effective with the addition of an anti-reflective (AR) coating to the backside of your lenses. With AR coating, your sunglasses will not only help shield glare reflecting off surfaces in front of you, but they will also help prevent glare when the sun is behind you.
Polarized lenses are available both with prescription and non-corrective lenses. If you think prescription polarized sunglasses may be the right choice for you, talk to an eye doctor to find out more.