Ask the Expert: Should I Be Wearing Blue Light Blocking Glasses?

Welcome to our Ask the Expert series, in which local health and fitness experts answer your wellness questions. Here, Dr. Matthew Gardiner discusses the ins and outs of blue light. Got a question of your own? Email tyannone@bostonmagazine.com. 

Photo via iStockphoto.com/skynesher

Do you spend a lengthy amount of time staring at a screen or some other kind of artificial light all day? Are you notorious for scrolling through your phone before laying down for bed? Chances are, you’re not spending that time thinking about what’s going on in your retinas, or more specifically, with your sleep cycle.

The glow from these devices is called blue light. To break it down, sunlight contains red, orange, yellow, green, and blue light rays. The rays on the red side of the spectrum have longer wavelengths and emit less energy, whereas on the blue side of the spectrum, rays have shorter wavelengths and produce more energy.

Dr. Matthew Gardiner, an ophthalmologist from Massachusetts Eye and Ear flushed out what’s fact and what’s fiction when it comes to how blue light affects our eyeballs—and whether or not blue light blocking glasses are actually a worthwhile investment.

Ask the Expert: Should I Wear Blue Light Blocking Glasses?

The Answer: Not necessarily.   

The Details: 

“Blue light is simply one end of the visible electromagnetic spectrum,” Gardiner says. “With lower frequency red on one end and higher frequency blue on the other. It can come from many things we encounter throughout the day, from computer screens and LED bulbs to natural sources like the sun and sky.”

He explains that although blue light is higher energy than red, it is not at a level that can cause harm to your eyes. Which poses some confusion because of the widespread claims that we all should be wearing blue light blocking glasses to protect our peepers. “The confusion comes from the fact that ultraviolet light is harmful,” Gardiner says. And it’s also why we’re told not to look directly at the sun when we’re outside. This ultraviolet light is just past blue light on the spectrum, but that doesn’t mean we can extrapolate that ultraviolet light is bad and blue light is just “a little bad,” because there’s just no evidence that blue light can hurt us, explains Gardiner.

Although there is no evidence that the glow from LED lights and computer screens is harmful to your eyes, there is mounting evidence that blue light can reset your natural sleep clock.

According to a study from Harvard, comparing 6.5 hours of exposure to blue light to the same exposure of green light, the blue light suppressed melatonin, a hormone that regulates sleep, for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours). Meaning, it’s taking people longer to fall asleep, and stay asleep, after being exposed to the light and not all light is created equal at nighttime. Blue light is great during the day in terms of boosting attention, reaction times, and mood, but doesn’t serve you well at night when you’re trying to wind down for the evening.

“We recommend avoiding screens for about an hour or two before bedtime,” Gardiner says. “It’s been conjectured we have evolved over millenia to wake up to the ‘bluer’ light of the morning and get sleepy with the more red-shifted light of a campfire.” So when we’re endlessly scrolling, staring into a bright screen, we’re giving our brain the signal that it’s time to be awake when we should be getting ready to go to sleep—making it hard to actually fall asleep when the time comes.

So when it comes down to all of these blue light blocking glasses out on the market now, Gardiner says he can’t criticize people for trying them, but he advises his patients not to spend more than $20-$30. “There is no safety reason for wearing them,” he says. “These glasses have been marketed for all sorts of reasons without real evidence.” Some of his patients have noted that they have felt more comfortable while driving at night with yellow-tinted glasses, but others have experienced no real difference.

“The discomfort some people may feel from extensive screen use is more from dryness than anything else,” Gardiner explains. “Our lifestyle has become much more screen-centric lately, such that we now spend hours at work studying the same glowing rectangle without interruption. Taking breaks several times per hour and looking away from the screen periodically can help.”

Bottom line: Blue light affects our sleep, but does not cause harm to our eyes. Measures like just looking away from your computer throughout the day and avoiding screen time at night, close to bed, are more worth your time than a $95 pair of glasses.