“Mommy, why is the sky blue?”
It’s a question both of my kids asked me when they were little, along with one jillion other questions they pummeled me with daily. At the time, I said I thought it had something to do with the ocean’s reflection in the sky, and that I would look it up. (Spoiler alert: I didn’t.) Six years later, though, after researching for this story, I finally have the correct answer: blue light, also known as HEV (high-energy visible) light.
“Light from the sun travels through the atmosphere and is all around us during daylight hours,” says Tracy May-Harriott, Priori® Skincare’s Global Director of Education. Sunlight is made up of all different colors of light, but “the shorter, high energy blue wavelengths crash into air molecules causing blue light to scatter everywhere.” So when we look up at the sky, we see it as blue.
Even after the sun sets, modern technology lights up our lives with HEV: TVs, laptops, phones, and tablets, as well as fluorescent and LED lighting, are all sources of blue light. Basically, HEV is everywhere, and it’s unavoidable: here’s why the ubiquity of blue light matters to you and your skin.
Channeled correctly, blue light can help certain skin conditions. For example, “When blue light is used in conjunction with aminolevulinic acid, it treats actinic keratoses, which are precancerous lesions caused by sun exposure,” says David E. Bank, MD, a dermatologist in Mt. Kisco, New York. “It can also destroy acne-causing bacteria,” he notes, and can reduce inflammation in psoriasis and eczema patients.
But there’s a dark side to blue light, too.
Once upon a time, it was thought that only UVB, the rays that literally burned our skin, were responsible for sun damage. To this day, in fact, the SPF number on a bottle of sunscreen refers only to the level of protection against UVB rays. It wasn’t until the late 1980s that UVA rays were recognized as a skin hazard as well. Overexposure to UVA can lead to hyperpigmentation (the uneven darkening of skin), the breakdown of skin-supporting proteins collagen and elastin (leaving skin wrinkled and sagging), and skin cancer.
Well, it looks like we’re at another turning point in understanding how sunlight causes damage. “There is an ever-growing body of evidence proving the damage created by blue light on the skin,” says May-Harriott, with studies equating the harmful effects of HEV to those of UV rays.
Just as with UV, when blue light penetrates the skin, it causes free radical damage, which in turn leads to hyperpigmentation and damage to the skin’s proteins. (So far, no study has linked HEV exposure to skin cancer.) According to Qiang Qiu, the lead scientist for Unilever’s™ global skincare research and development, a recent study delivered interesting findings on HEV. “We asked volunteers to go out in the sun wearing either UV or visible light filters, to study their effects on skin hyperpigmentation responses,” says Qiu. “Interestingly, they found visible light alone is sufficient to induce skin darkening, and the degree of darkening is the same as from UV.”
Even your indoor exposure is enough to cause “sun” spots: According to Unilever research, eight hours a day, four days a week in front of a computer is equal to 20 minutes of noon sun. “This radiation is enough to cause cellular oxidative damage and skin’s hyperpigmentation response,” says Qiu. (Eight screen hours a day? Pssh. That’s nothing.)
So, how can we protect ourselves from blue light? Sunscreen? Screen-screen? Not just any “screen” works. Sunscreens are designed to either absorb or reflect UV rays, which range from 280 – 315 nanometers (nm) for UVB and 315 – 400 nm for UVA. At 400 – 490 nm, HEV is longer (which also means it penetrates deeper into your skin), and the only sunscreen ingredients that effectively block those wavelengths are non-nanoparticle zinc oxide and titanium dioxide, commonly known as mineral sunscreens.
But those longer wavelengths also mean that “Blue light penetrates the skin more deeply than UV rays, creating damage deep within the skin,” says May-Harriott. “So simply wearing a broad-spectrum sunscreen is not enough. We need specific protection from HEV light now in our everyday skincare to tackle the damage caused by our technology-driven lifestyle.”
Skincare products boasting blue-light protection are starting to pop up, featuring mineral sunscreens fortified with targeted antioxidants that show promise in their ability to neutralize the free radicals triggered by HEV. A few worth trying: Supergoop!® Smooth and Poreless™ 100% Mineral Matte Screen SPF 40 ($38) with butterfly bush extract; Iris&Romeo™ Best Skin Days™ ($68) which has SPF 25, vitamin C (and the perfect amount of dewy, color coverage); and Priori® Tetra fx250™ ($90), with SPF 50 and soliberine.
To safeguard your skin around the clock, try SkinMedica® Lumivive® System ($265). This pair of products includes a daytime serum that provides a literal barrier to blue light (and pollution) and a nighttime complex that supercharges the repair process while your skin is (finally!) getting a blue-light break.
There’s one more, even sneakier way that blue light can screw up your skin: by depriving you of sleep. “About nine years ago, researchers discovered that there are certain cells in your eyeball called melanopsin cells,” says sleep specialist Michael Breus, PhD. “These cells react specifically to the 460 nanometer wavelength, and they send a signal to your pineal gland to turn off the melatonin faucet.” And when that melatonin doesn’t come, sleep doesn’t either.
Sleep deprivation can increase your body’s level of stress hormones, triggering acne, psoriasis, and eczema. It also means your skin is getting less time to repair itself. And if you think switching your devices to Night Shift® mode is your solution, I’ve got some bad news: It’s a great idea in theory, but according to a study last year, the Night Shift mode is insufficient. A better bet: Sleep Doctor® Luminere™ Blue Light Blocking Glasses (two pairs for $50). They feature an amber filter that blocks the blue, so your melatonin arrives on schedule.
SkinMedica® is an Allergan®-owned skincare line.
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