A new study into blue light and retinal cells have linked blue light exposure to a disruption in circadian rhythm.
Researchers at Salk Institute demonstrated the effects of blue light on a small cluster of light-sensitive cells in the retina.
The retina is a sensory membrane at the back of the eye. The retina is responsible for converting light into neural signals for your brain to process.
When exposed to blue light, retinal cells produce a protein known as Melanopsin which suppresses the production of Melatonin – the hormone responsible for regulating sleep. This balance helps control our consciousness, sleep cycles and general alertness throughout the day.
Researchers have now found that by encouraging Melanopsin production at unnatural times of the day, you are effectively pressing a biological ‘reset button’ on your internal body clock. By disrupting your circadian rhythm and halting Melatonin production, Melanopsin offsets tiredness in the evenings.
This can lead to fatigue, difficulty focusing, and fluctuations in mood. In a recent survey of people with depression, most participants reported getting a small amount of sleep from day to day.
The danger of artificial blue light
The effect of blue light on your eyes, and subsequently your brain, is problematic. This is due to our increased reliance of digital devices for work and entertainment. While blue light from the sun is helpful, its effect on the brain becomes problematic when exposed at night.
Professor Sachin Panda, Salk Institute
A high energy visible (HEV) light range, blue light is emitted from the LED screens we use every day, penetrating to the back of our eyes and sending various signals to our brains via the production of proteins and hormones. These signals help us keep alert during the day, but at night they keep us in an unnaturally alert.
“We are continuously exposed to artificial light, whether from screen time, spending the day indoors or staying awake at night,” says Sachin Panda, senior author of the study. “This lifestyle causes disruptions to our circadian rhythms and has deleterious consequences on health.”
Over-exposure to blue light has shown to have a significant impact on our mental and physical wellbeing. Over-exposure is particularly damaging for children, whose eyes have not fully developed.
Salk Institute hopes to better understand Melanopsin and the impact of light exposure on our eyes. Hopefully, this may lead to new developments in the treatments in the future.