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Natural blue light, which lies in the portion of the electromagnetic spectrum that is visible to the human eye, has several health benefits. These include regulating the body’s circadian rhythm, boosting alertness, and increasing one’s overall feeling of wellbeing. However, the same cannot be said about the stronger artificial blue light, which has permeated our households by way of digital devices such as televisions, smartphones, laptops, and gaming systems. Previous studies have shown that extended exposure causes eye strain, fatigue, headaches, and sleeplessness. Now, new research by Ohio’s University of Toledo (UT) has found that the blue-tinted screens of our addictive gadgets may be accelerating macular degeneration – a condition that results in significant vision loss, eventually leading to blindness.
Macular degeneration, caused by the weakening of the eye’s photoreceptor cells, affects over 2 million Americans annually. Since the affliction mostly impacts people in their 50s and 60s, it has traditionally been believed to be brought on by age. However, experiments conducted by the Toledo research team, led by assistant professor Dr. Ajith Karunarathne, has revealed that excessive exposure to artificial blue light may also be a factor. The scientists found that blue light causes retinal molecules – the cells that detect light and initiate signaling to the brain – to trigger harmful particles. The toxic molecules kill the photoreceptors, which are responsible for absorbing and converting light into electrical signals and sending them to the brain for interpretation.
"It's toxic. If you shine blue light on retinal, the retinal kills photoreceptor cells as the signaling molecule on the membrane dissolves. Photoreceptor cells do not regenerate in the eye. When they're dead, they're dead for good," said Kasun Ratnayake, a Ph.D. student researcher and co-author of the study.
The researchers say this is because our corneas are unable to protect us from blue light waves, which have shorter wavelengths, the way they can from colors like red and green, which have longer wavelengths. Hence, the energetic color is easily able to penetrate our light-sensitive retinas and cause irreversible damage.
“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,” said Dr. Karunarathne. Meanwhile, the expert recommends protecting your eyes by wearing sunglasses that can filter both the sun’s UV and blue light and avoiding using smartphones, laptops, and other digital devices at night.
The Toledo team, that published its findings in the journal Nature on July 5, 2018, next plans to study the impact on the eyes from daily exposure to the blue light emitted by the digital devices. The researchers hope it will enable them to find a way to intercept the toxic reaction caused by the combination of retinal and blue light and help protect the vision of children growing up in a technology-driven world.
Resources: Theguardian.com, Fortune.com, Zmescience.com