Blue light emitted by smartphones and laptops accelerates blindness by making a molecule in our eyes toxic, according to a new study

Shutterstock/Marcos Mesa Sam Wordley
  • A new study found that blue light can cause macular degeneration, one of the leading causes of blindness.
  • Blue light harms our vision by damaging the eye’s retina, the researchers say.
  • The study found that blue light turns a molecule in the eye into a poison that kills photoreceptor cells, which do not regenerate.
  • Special sunglasses that filter blue light might help, but specialists aren’t sure how much good they actually do.

Staring at screens all day isn’t good for us – we know this. It can cause eye strain, sometimes called computer vision syndrome, and the light is so bright it can mimic sunlight, mess with our hormones, and prevent us from feeling sleepy.

And according to a new study, published last month in the journal Scientific Reports, the blue light emitted by our phones, tablets, and laptops might increase our chance of becoming blind. Previous studies have found that blue light is harmful, but researchers from the University of Toledo say it can make molecules “toxic.”

The team found that shining blue light on eye cells transforms vital molecules into a cell-killing poison that can lead to age-related macular degeneration, one of the biggest causes of blindness worldwide.

“We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it,” Ajith Karunarathne, an assistant professor in the university’s Department of Chemistry and Biochemistry who helped write the study, said in a press release.

“It’s no secret that blue light harms our vision by damaging the eye’s retina,” Karunarathne said. “Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration, such as a new kind of eye drop.”

Macular degeneration occurs when photoreceptor cells in the retina die. They do not regenerate, so “when they’re dead, they’re dead for good,” said Kasun Ratnayake, a doctoral student researcher who also wrote the study.

The photoreceptor cells need molecules called retinal to sense light. But the researchers found that blue light can cause retinal to change and kill photoreceptor cells by dissolving some of their membranes.

The team added retinal molecules to other body cells – like cancer cells, heart cells, and neurons – which also died when exposed to blue light. Without the retinal, blue light had no effect on the other cells, the researchers said.

“No activity is sparked with green, yellow, or red light,” Karunarathne said. “The retinal-generated toxicity by blue light is universal. It can kill any cell type.”

The researchers also found that a molecule in our eyes and body called alpha-Tocopherol, a natural antioxidant, stops affected cells from dying. But as we age or our immune system takes a hit, we lose the ability to fight against the toxic-retinal attack – and that’s when the damage occurs.

Karunarathne suggested using special sunglasses that filter UV and blue light to try to combat the effects, but experts are unsure whether they do that much good.

You can also try to avoid smartphones and laptops when it’s dark – something you should be doing anyway if you want to get a good night’s sleep.

“Every year, more than 2 million new cases of age-related macular degeneration are reported in the United States,” Karunarathne said, adding: “We hope to find a way to protect the vision of children growing up in a high-tech world.”

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