Screens are killing your eyeballs, and now we know how

Blue light’s rap sheet is growing ever longer. Researchers have connected the high-energy visible light, which emanates from both the sun and your cell phone (and just about every other digital device in our hands and on our bedside tables), to disruptions in the body’s circadian rhythms. And physicians have drawn attention to the relationship between our favorite devices and eye problems, ranging from everyday eye strain to
glaucoma to macular degeneration.

Humans can see a thin spectrum of light, ranging from red to violet. Shorter wavelengths appear blue, while the longer ones appear red. What appears as white light, whether it's from sunlight or screen time, actually includes almost every color in the spectrum. In a recent paper published in the journal Scientific Reports, researchers at the University of Toledo have begun to parse the process by which close or prolonged exposure to the 445 nanometer shortwave called "blue light" can trigger damage irreversible damage in eye cells. The results could have profound consequences for consumer technology.

 Catastrophic damage to your vision is hardly guaranteed. But the experiment shows that blue light can kill photoreceptor cells. Murdering enough of them can lead to macular degeneration, an incurable disease that blurs or even eliminates vision.


Blue light occurs naturally in sunlight, which also contains other forms of visible light and ultraviolet and infrared rays. But, Karunarathne points out, we don’t spend that much time staring at the sun. As kids, most of us were taught it would fry our eyes. Digital devices, however, pose a bigger threat. The average American spends almost 11 hours a day in front of some type of screen, according to a 2016 Nielsen poll. Right now, reading this, you’re probably mainlining blue light.

Apple offers a “night shift” setting on its phones, which allow users to blot out the blue and filter their screens through a sunset hue. Aftermarket products designed to control the influx of blue light into our irises are also available, including desktop screen protectors. There are even blue light-filtering sunglasses marketed to specifically to gamers. But as the damage done by blue light becomes clearer—just as our vision is getting blurrier—consumers may demand bigger changes.

Going forward, Karunarathne plans to stay in data-collection mode. “This is a new trend of looking at our devices,” he says. “It will take some time to see if and how much damage these devices can cause over time. When this new generation gets older, the question is, by that time, is the damage done?” But now that he appears to have identified a biochemical pathway for blue light damage, he’s also looking for new interventions. “Who knows. One day we might be able to develop eye drops, that if you know you are going to be exposed to intense light, you could use some of those… to reduce damage.”

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