Blue light from digital devices and the sun transforms vital molecules in the eye’s retina into cell killers.
A study published in Scientific Reports shows how the effects of blue light lead to age-related macular degeneration, a leading cause of blindness.
Macular degeneration is the death of photoreceptor cells in the retina. It is an incurable eye disease that results in significant vision loss starting on average in a person’s 50s or 60s.
“We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it,” said Ajith Karunarathne, assistant professor in the UT Department of Chemistry and Biochemistry.
“It’s no secret that blue light harms our vision by damaging the eye’s retina.
“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.”
Photoreceptor cells need molecules called retinal to sense light and trigger a cascade of signaling to the brain.
The research found that blue light exposure causes retinal to trigger reactions that generate poisonous chemical molecules in photoreceptor cells.
“It’s toxic. If you shine blue light on retinal, the retinal kills photoreceptor cells as the signaling molecule on the membrane dissolves,” said Kasun Ratnayake, a PhD student researcher working in Karunarathne’s cellular photo chemistry group.
“Photoreceptor cells do not regenerate in the eye. When they’re dead, they’re dead for good.”
As a safety measure, Karunarathne advises users to wear sunglasses that can filter both UV and blue light outside and avoid looking at cell phones or tablets in the dark.