Whether you call them sunglasses, sunnies or shades, those plastic lenses you wear across your eyes are designed to protect you against harmful UV rays and the effects of direct sunlight. To that end, most of us buy sunglasses with polarized lenses and built-in UV protection. The latter is the more important of the two.
A recent Yahoo! News post sported a headline which encouraged readers to ditch their cheap sunglasses in favor of a new pair with polarized lenses. The article then went on to discuss the importance of UV protection against ultraviolet light and polarization to prevent sun glare.
Mixed Messages About Shades
Nothing about the article was scientifically inaccurate. However, it could be construed as both confusing and misleading. Why? For starters, UV protection has little to do with price. Polarized sunglasses may be slightly more expensive, but not by much. Yet the most confusing aspect is this: at the bottom of the post are reviews of a variety of pairs of sunglasses ranging from the $10 range up to hundreds of dollars.
So which is it? Are we supposed to ditch our cheap sunglasses or keep buying them? For that answer, we turn to Salt Lake City’s Olympic Eyewear. Olympic has been in the eyewear business for years, designing and selling more than two dozen brands of designer-like and fashion sunglasses.
More About UV Protection
The Yahoo! News article correctly pointed out that UV exposure can lead to a variety of eye problems including photo keratitis, cataracts, photo conjunctivitis, and even cancer. It incorrectly draws a correlation between UV protection and price.
Olympic explains that UV protection is achieved by embedding a filter within the lens. The filter is transparent to the naked eye. It blocks out UV rays at wavelengths of between 10 nm and 400 nm. A pair of sunglasses rated UV 400 blocks all ultraviolet rays. Another pair rated at 300 blocks UV rays up to 300 nm.
What must be understood is that designer sunglasses do not offer more UV protection because they are more expensive. A $25 pair rated UV 400 offers the exact same protection as a $250 pair with the same rating. Price and UV protection have nothing to do with one another.
More About Polarization
Polarized sunglasses are sunglasses with a special film applied to the outside surface of the lenses. This film is essentially a filter. It filters out visible light either horizontally or vertically, taking care of the sun glare problem.
Sun glare occurs when the sun reflects off a surface like water or snow. Reflection causes light waves to travel in multiple directions. That’s what causes glare. Your eyes see the light but has trouble sorting it out because it’s moving every which way. Polarized sunglasses filter out most of the unwanted light so that your eye sees much better.
Polarized sunglasses sometimes cost more than their non-polarized counterparts. Generally, this is due only to the customer’s willingness to pay more. The cost of manufacturing and applying the polarization film costs pennies per lens; certainly not enough to justify an extra $100 per pair.
Don’t Be Fooled
The lesson in all of this is pretty straightforward: do not be fooled into thinking you are getting more protection because you are paying more. It is just not true. If you want to know how much protection a pair of sunglasses offers, read the attached label. You can spend hundreds of dollars on a pair of designer sunglasses if you want to, but you don’t have to. A good pair of polarized sunglasses with UV protection can be affordable.