Kasun Ratnayake, a PhD student at the University of Toledo and one of the authors of the study explained that if the blue light is shone on the retina, it kills the photoreceptor cells of the retina and the signalling molecules called retinal on the retinal membrane dissolves.
The blue light tablets, smartphones, and laptops emit is so bright we can see our screens on a sunny day. "Some cell phone companies are adding blue-light filters to the screens, and I think that is a good idea".
As more research is needed, those involved in the study say to avoid looking at screens at night - and that scientists should look into developing an eye drop that could perhaps ward off some of the damage caused by the ubiquity of screens with blue light, WTOL reported. "Photoreceptor cells do not regenerate in the eye". However, digital devices, such as computers, televisions, and smartphones, also emit blue light, and we spend an very bad lot of time staring directly at those screens from a close distance. Researcher Ajith Karunarathne said that "We are being exposed to blue light continuously, and the eye's cornea and lens can not block or reflect it".
They found that exposing the eye to blue light causes a reaction which leads an essential light-sensitive protein in the retina, known as retinal, to generate poisonous molecules in photoreceptor cells, resulting in their death.
Macular degeneration, which affects around 2.4% of the adult population in the United Kingdom, is a common condition among those in their 50s and 60s that results in significant vision loss. "When they're dead, they're dead for good", said Ratnayak.
In the lab, the researchers combined retinal with various cells from the body, including photoreceptor cells, neurons, and heart cells. No other visible spectrums of light such as green, yellow or red triggered the same retinal process as blue light. He explained that their experiments have shown that this exposure can lead to slow macular degeneration and a new therapy is developed to block this effect. "It can kill any cell type".
The researchers also discovered that alpha tocopherol, a molecule derived from Vitamin E, can prevent this cell death. But as we age, or if the immune system is suppressed, we lose the ability to fight against attacks by retinal and blue light.
The lab now is measuring light coming from television, cell phone and tablet screens to get a better grasp of how the cells in the eyes respond to everyday blue light exposure.