Blue light is a buzzy idea right now. There are glasses to shield your eyes from it, and you’re constantly told to power down your digital devices before bed so that their blue light doesn’t mess with your sleep. But what exactly is blue light, and how worried about it should you be? We went to the experts to get answers.
What exactly is blue light?
We usually talk about blue light as the glare that comes from our smartphone, laptop, TV, or any other digital device. But blue light is actually all around us—because it’s simply a wavelength on the visible spectrum. “Blue light has shorter wavelengths and higher energy than other types of visible light, such as red, because of where it falls on the visible spectrum,” says Kim Van Fleet, a lecturer in environmental studies. “The most obvious source of blue light is actually from the sun, though it’s also emitted via an assortment of man-made digital devices and from fluorescent and LED light bulbs.”
Is blue light bad for your sleep?
There’s lots of research on how blue light impacts sleep, and Michael Breus, clinical psychologist, sums up what we know so far: “Blue light suppresses melatonin production, the hormone that naturally summons sleep,” says Breus. This is why it can take longer to nod off if you’ve been staring at your phone screen before bed, and why sleep experts recommend putting away all electronic devices at least 30 minutes before bedtime.
So, does blue light affect circadian rhythm too?
Exposure to blue light can also impact our internal body clock. Our circadian rhythm is regulated by natural patterns of lightness and darkness, so being exposed to light when we normally wouldn’t (like at bedtime) messes with the mechanism—and this can affect other bodily functions down the line. “Blue light alters our circadian rhythm, which can impact our cardiovascular, metabolic, cognitive, and immune health over time,” Breus says.
On the other hand, there are times when a little blue light exposure can actually be beneficial, especially during times of the year (like the long, dark days of winter) when we tend to get less natural light. “Since it helps set the body’s internal body clock, it can make us more alert, influence our ability to understand and remember things, and elevates our mood and energy levels,” says Van Fleet. This is why people with seasonal affective disorder (SAD) are often told to try light therapy to feel better.
What does blue light do to your eyes?
While there isn't enough research to say that blue light emitted from digital screens alone can cause eye issues, being exposed to this type of light in various ways (from the sun, lights, screens, etc.) may lead to damage over time. “When blue light reaches the eyes, most of it passes right through the lens and cornea to the retina, where over time, it can cause damage,” says Van Fleet. “Chronically being overexposed to blue light could even lead to the development of age-related macular degeneration.”
At the same time, ophthalmology experts claim that it isn't necessary to spend extra money on eyewear that claims to block blue light, but there are things you can do to minimise the negative effects of staring at digital screens for a long time. If your eyes have ever felt dry, blurry, or you've had trouble focusing after a long period in front of your laptop, that’s how you know your eyes need a break. Here are Van Fleet’s best tips for doing just that:
- Sit at least an arm's length away from your screen and take breaks from staring your computer to reduce eye strain.
- Choose glasses over contact lenses and apply artificial tears to combat dryness.
- Consider anti-glare screen filters and reduce brightness, which can also help avoid eye strain.
Is blue light bad for your skin?
You may have heard of “Netflix face,” or premature skin aging that results from too much time spent in front of electronic screens. “Recent research has found there are biological effects, a.k.a. skin damage, associated with exposure to blue light from smartphones and other digital screens that emit it,” says Van Fleet.
If it sounds a little far-fetched, it’s not; just like the sun’s UV rays can cause oxidative stress that ages skin, blue light from digital screens may affect the skin in a similar way. An easy way to slow down the potential effect to the skin is to monitor how much time you spend in front of screens, but you can also reduce your overall blue light exposure by replacing LED light bulbs with ones in the yellow or red range, says Van Fleet.