Health & Wellness

Another Reason to Limit Your Screen Time

Our phones and laptops are probably taking a toll on our physical health

Photo: iStock/phive2015.


It’s commonly advised that we avoid computer and cellphone screens in the hours before sleep because the blue light they emit can disrupt sleep. Now a new study suggests that blue light may also accelerate aging.

The study looked at how fruit flies adapt to living around blue light and found that it impairs their ability to fly by damaging their brain and retinal cells. The results were published in the journal Aging and Mechanisms of Disease by researchers at Oregon State University.

“The fact that the light was accelerating aging in the flies was very surprising to us at first,” Jaga Giebultowicz, a professor of integrative biology at the university, said in a statement.

The new study was based on previous studies that found fruit flies’ lifespans were shortened when they were kept for long hours in light, but only recently did researchers find that blue light is the most damaging light in the spectrum. The researchers in the most recent study subjected flies to 12-hour cycles of darkness and blue-light exposure and found that blue light shortens the flies’ lifespan by interrupting their circadian rhythm, which regulates sleep and hormones, particularly stress hormones, in the body.

“Stress-response, protective genes were expressed if flies were kept in light. We hypothesized that light was regulating those genes,” Giebultowicz said. “We looked at the spectrum of light. It was very clear cut that although light without blue slightly shortened their lifespan, blue light alone shortened their lifespan very dramatically.”

Surprisingly, researchers also found blue light had the same effect on flies even when it didn’t reach their eyes. They realized that after subjecting mutated flies without eyes to the same test. In normal circumstances, flies avoid blue light at every opportunity.

“There is evidence suggesting that increased exposure to artificial light is a risk factor for sleep and circadian disorders,” she said. “With the prevalent use of LED lighting and device displays, humans are subjected to increasing amounts of light in the blue spectrum.”

The good news is that you can turn off blue light on many of your devices, such as your Mac or iPhone. If you work late into the night, glasses with amber lenses can help protect your eyes, and perhaps even lengthen your lifespan.