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Question: Summertime is almost here and I want to get a new pair of sunglasses. What should I buy to best protect my eyes?
Answer: It’s well known that prolonged exposure to sunlight can increase the risk of getting skin cancer. But, in some respects, the eyes are even more vulnerable than the skin to the sun’s powerful rays.
If you stare at the sun, you can permanently damage your vision in almost no time. Of course, most people have enough sense to avoid looking directly at the sun. Yet even indirect sunlight can be harmful – particularly a form of solar rays called ultraviolet (UV) radiation.
UV rays are invisible but they carry a lot of energy. They can speed up the natural aging process of the eyes and contribute to several sight-limiting conditions, including:
- Cataracts – a clouding of the lens of the eye. Eventually, vision can become so impaired that the natural lens may need to be replaced with an artificial lens. In poor countries, where patients have limited access to surgery, cataracts are a leading cause of blindness.
- Pterygium – a growth of tissue on the whites of the eyes. It can spread over the cornea – the front window of the eye – and interfere with sight. In advanced cases, patients may need surgery to remove the excess tissue.
Another concern is visible light in the blue portion of the color spectrum. Studies suggest blue light may accelerate or worsen another form of vision loss called age-related macular degeneration.
There’s certainly good reason to guard your eyes against the sun. And it’s important to know that the eyes require a longer period of protection than the skin, says Dr. Harmeet Gill, an ophthalmologist at Sunnybrook Health Sciences Centre and Mount Sinai Hospital in Toronto.
The sun causes the most harm to the skin when it’s overhead, from 11 a.m. to 3 p.m. between April and September in Canada. At those times, the sun’s rays travel through less atmosphere, making them especially intense.
But the sun poses a significant risk to the eyes even when it’s low in the sky. In fact, the lower angle gives the sun’s rays a direct pathway into the eyeball. Think of how hard it is to drive on the highway when you’re heading into the rising or setting sun.
Furthermore, UV rays can penetrate clouds and reflect off many different surfaces such as snow, sand and water.
“To protect your eyes, you should be wearing sunglasses, day-long, year-round and even when it’s cloudy,” says Dr. Gill. “I know it sounds a bit crazy, but that’s what the research actually shows.”
He adds that the best protection is provided by close fitting, wrap-around sunglasses that also block sunlight from the sides. Wearing a wide-brimmed hat also helps to keep the sun out of the eyes.
When you’re picking sunglasses, you will want to find a pair that shields against both UV rays and blue light.
Medium to dark lenses with a grey or a slightly brown or green tint will filter out most of the blue light, according to Health Canada’s website.
However, there is no way you can tell if sunglasses guard against UV light simply by their appearance. Companies will usually display labels stating that their sunglasses have a special coating that blocks UV rays. (Some labels may say the glasses absorb up to 400 nanometers of UV radiation, which is equivalent to almost 100% UV protection.)
But there’s a catch – companies in Canada are following voluntary industry standards for UV protection and no independent agency is actually checking if the claims are accurate, says Dr. Samuel Markowitz, a professor in the Department of Ophthalmology at the University of Toronto.
“As it stands now, it is basically self-declared compliance,” he adds. In other words, consumers can’t be certain they’re getting what’s stated on the label.
Marie-France Faucher, a federal government spokesperson, said in an email that companies are prohibited under Canada’s Competition Act from making false claims. She adds that the Competition Bureau would investigate “all allegations of false or misleading representation.”
Another government spokesperson, André Gagnon, said in an email “Health Canada is not aware of any health or safety issues relating to non-prescription sunglasses.” Nor has it received any reports of problems.
So, without any formal complaints, there are no investigations. What’s more, “there are no plans to introduce mandatory requirements for this product category,” notes Mr. Gagnon.
In some other countries that also rely on voluntary industry compliance, random spot checks have found a significant portion of sunglasses incorrectly labeled – promising UV protection when it is absent.
Dr. Markowitz suggests that Canadians should try to “buy from a reputable company.” What’s a reputable company? “One that probably has large market share and has been around for years and has a reputable public track record. Try to avoid unknown suppliers,” he says.
Still, the customer is relying on trust. To eliminate the uncertainty, Dr. Markowitz says you could order a custom-made pair from an eyeglasses supplier, stipulating that you want a UV block. While you’re at it, you could also request shatter-resistant, optical-quality lenses for added protection and clarity of vision.
Buying custom-made sunglasses may seem overly cautious. But in a system that relies on voluntary compliance, it’s one way to boost your chances of getting a product that will properly protect your eyes.
Paul Taylor, Sunnybrook’s Patient Navigation Advisor, provides advice and answers questions from patients and their families. His blog, Personal Health Navigator, is reprinted on Healthy Debate with the kind permission of Sunnybrook Health Sciences Centre. Follow Paul on Twitter @epaultaylor.
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I wonder if the “Transistions” coating on prescription glasses has UV protection. the Optometrist told hubby he is starting a cataract in one eye. he wont wear sunglasses!