Daily Exposure to Blue Light May Damage Cells in the Brain and Retinas

The study was based on experiments conducted on the Drosophila melanogaster, the common fruit fly. The work was led by Jaga Giebultowicz, a researcher in the OSU College of Science.

It examined how flies responded to daily 12-hour exposures to blue LED light, similar to the prevalent blue wavelength in devices like phones and tablets. Those flies exposed to blue light had shorter lives compared to flies kept in total darkness or those kept in light with the blue wavelengths filtered out.

The flies exposed to blue light exhibited damage to their retinal cells and brain neurons and had impaired locomotion. The study included mutant flies that did not have eyes, and even those witnessed brain damage and locomotion impairments. This means that the harm done by blue light occurs regardless of whether the victim sees it.

"The fact that the light was accelerating aging in the flies was very surprising to us at first," said Giebultowicz, also a professor of integrative biology.

"We'd measured expression of some genes in old flies, and found that stress-response, protective genes were expressed if flies were kept in light. We hypothesized that light was regulating those genes. Then we started asking, what is it in the light that is harmful to them, and we looked at the spectrum of light. It was very clear cut that although light without blue slightly shortened their lifespan, just blue light alone shortened their lifespan very dramatically."

Although, we cannot discount the fact that natural light is crucial for the body's circadian rhythm, we have to acknowledge that artificial light is a risk factor for sleep and circadian disorders.

The dangers of LED lighting

"And with the prevalent use of LED lighting and device displays, humans are subjected to increasing amounts of light in the blue spectrum since commonly used LEDs emit a high fraction of blue light. But this technology, LED lighting, even in most developed countries, has not been used long enough to know its effects across the human lifespan,"  added Giebultowicz. 

To protect ourselves from this light, the researchers suggest using eyeglasses with amber lenses and setting phones, laptops and other devices to block blue emissions.

The study is published in Aging and Mechanisms of Disease.