A team of scientists at the University of Toledo in the United States has revealed that prolonged exposure to blue light triggers the release of toxic molecules in photoreceptor cells that, in time, could lead to vision issues. In time, this can lead to macular degeneration, an ophthalmic disorder that causes destruction of central vision. In other words, the blue light, which has a shorter wavelength and emits more energy compared to other colors, can gradually damage vision.
Macular degeneration, a real problem
“We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it […] 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 down the process of macular degeneration, such as a new kind of eye drop,” said Ajith Karunarathne, assistant professor in the Department of Chemistry and Biochemistry of Toledo University.
Macular degeneration, which in the UK affects approximately 2.4% of the population, is a common disorder among people aged 50 or 60, resulting in significant loss of visual acuity. This condition is caused by the death of photoreceptors, light-sensitive cells present in the retina.
Senile macular degeneration is the main cause of vision loss in the United States and, although it does not cause total blindness, it has a significant impact on the day-to-day activities of people affected, such as reading or recognizing faces.
Photoreceptor cells require certain retinal molecules to sense light and trigger signal transmission to the brain thus forming the images. Scientists have found that retinal molecules introduced into other types of cells in the body, such as cancer, heart, or neurons, cause their death when exposed to blue light. They also noticed that neither this type of light nor the retinal molecules have an effect on cells if they act independently and are not associated.
“No activity is sparked with green, yellow or red light […] The retinal-generated toxicity by blue light is universal. It can kill any cell type.” said Dr. Karunarathne.
d-Alpha-Tocopherol is a naturally-occurring form of vitamin E
Researchers have discovered that a molecule called alpha tocoferol, a natural antioxidant found in the eye and the rest of the body, stops the death of cells but does not provide any protection for the elderly whose immune system is weakened. At this point the real injuries occur. People who want to protect their eyes from these unwanted effects are advised to wear glasses with lenses provided with both a blue light filter and a UV-resistant filter and also not to use mobile phones or tablets in the dark.
The study can be read on Nature magazine.
