The blue light emitted from the screens of cell phones and computers could accelerate blindness, according to new research.
Ongoing exposure to this light triggers a reaction in the eye’s light-sensitive cells that can speed up damage from macular degeneration, a relatively common condition in older adults. It can cause blurred or no vision in the center of the visual field, a study published in the journal Scientific Reports found.
“We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it,” Dr. Ajith Karunarathne, an assistant professor in chemistry and biochemistry at The University of Toledo, said in a statement.
It’s no secret that blue light harms vision by damaging the eye’s retina, but this experiment explains how this happens. Karunarathne said he hopes a better understanding of the mechanism behind the damage can lead to therapies that slow this incurable eye disease.
Macular degeneration is caused by death of photoreceptor cells in the retina. Typical onset starts between age 50 and 60. It is the leading cause of vision loss in the U.S., and can impair daily life. Tasks like reading the newspaper or driving a car might become more challenging or no longer possible for people who suffer from the condition, according to the Centers for Disease Control and Prevention.
Karunarathne’s lab found that if a blue light is shined on the retina, a reaction occurs that generates poisonous chemical molecules that can kill photoreceptor cells.
“It’s toxic,” Kasun Ratnayake, a PhD student researcher working in Karunarathne’s cellular photo chemistry group, said in a statement. This is particularly troubling because photoreceptor cells do not regenerate in the eye. “
“When they’re dead, they’re dead for good,” Ratnayake said.
A molecule called alpha tocopherol, a Vitamin E derivative and a natural antioxidant in the eye and body, can stop this destruction. But as a person ages, people lose the ability to fight against the attack.
“That is when the real damage occurs,” Karunarathne said.
People who want to protect their eyes from blue light should avoid looking at their cell phones or other blue-light emitting devices in the dark and consider wearing sunglasses, Karunarathne said.
Some cell phone companies are adding light filters that might be able to mediate damage to the eye said John Payton, visiting assistant professor in the The University of Toledo Department of Chemistry and Biochemistry.
The lab is now measuring light coming from television, cell phone and tablet screens to get a more nuanced understanding of how the eyes respond to everyday blue light exposure.
“We hope to find a way to protect the vision of children growing up in a high-tech world,” Karunarathne said.