Credit: Pixabay.

Doctors have long known that blue light emitted by your smartphone or laptop causes detrimental health effects. Blue light inhibits the production of melatonin, a hormone which is associated with sleep onset, keeping us awake and messing with our natural sleep cycles. Studies have also associated blue light with eye strain, obesity, and even certain types of cancer. Now, according to a new study, blue light fired by modern gadgets may be also steadily making us blind by triggering toxic chemical reactions in our eyes.

A research team at the University of Toledo, Ohio, performed a series of imaging tests on cell culture and found that blue light generates poisonous chemical reactions killing photoreceptors — specialized neurons that convert light into signals that the brain can decode as ‘vision’. No dangerous reactions were observed for green, yellow, or red light.

Once these photoreceptors are destroyed, there’s no way to regenerate them. “When they’re dead, they’re dead for good,” say the authors of the new study published in Scientific Reports.

With enough exposure, a person might develop macular degeneration, an incurable eye disease that causes blindness, typically starting in your 50s or 60s. In the United States, about two million new cases of age-related macular degeneration are reported each year.

It’s no secret that blue light harms our vision by damaging the eye’s retina,” said Ajith Karunarathne, assistant professor in the University of Toledo’s department of chemistry and biochemistry, and one of the study’s authors, in a statement. “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.”

Blue light can kill any type of cell, not just in the retina. Karunarathne hopes that his research might inspire colleagues to experiment with preventative remedies, such as an eye drop solution.

While such treatment is in development, we are advised to reduce our screen time to a minimum. Blue light-filtering eyewear may also help, although there is no peer-reviewed study thus far that can back up its efficacy.

In the future, Karunarathne and colleagues plan to study blue-light exposure from TVs, smartphones, and tablets to figure out what impact it has on our day-to-day lives.

“By learning more about the mechanisms of blindness in search of a method to intercept toxic reactions caused by the combination of retinal and blue light, we hope to find a way to protect the vision of children growing up in a high-tech world,” Karunarathne said.

A variety of Android phones and Apple’s iPhone have introduced blue light filters that allow you to adjust the warmth of the colors on your display. Here’s a guide on how to turn them on.  Even if you don’t have ‘night mode’, dimming LED lighting by 50% would be less bright to photoreceptor cells than a fluorescent or incandescent light.