If you’re reading this, you’re probably pretty smart. You prefer facts over fads. You care about your health and the health of those you care about. And you are almost certainly looking at a blue-light emitting screen right now. So let’s look at the facts around blue-light blocking glasses - and what they can and cannot do for you.
First, what is blue light?
Of all the colours in the visible light spectrum (colours seen by the human eye), blue (or blue-violet) light has the shortest wavelength and the highest energy. Our primary source of blue light is the sun and for centuries this was our only source of blue light. However, we now have many artificial sources of blue light, including LED lights, fluorescent and compact fluorescent light bulbs, flat screen LED televisions, computer monitors, smart phones and tablets.
Is blue light bad for your health?
Yes and no. Blue light is known to have significant health and wellness benefits. These include helping to boost alertness and mood, as well as improving memory and cognitive function. Blue light helps to regulate your circadian rhythm, which is your body’s natural wake and sleep cycle. It also contributes positively to eye growth and eye health in children.
But, as they say, too much of a good thing can be bad. With so many artificial sources of blue light, it affects us negatively too - especially with prolonged exposure to fluorescent lights and screens.
The negative effects of blue light
Due to its frequency, blue light easily passes through the front of the eye to the retina. Research shows that continued exposure to blue light can damage the retinal cells, potentially leading to premature visual degeneration, cataracts, growths or cancer. Children are particularly vulnerable to blue light, as their eyes absorb more blue light than adults.
Blue light, at the wrong time of day, also interferes with the production of melatonin - a hormone produced by your brain in response to darkness. Melatonin helps regulate your circadian rhythm. It helps you to get a decent night’s sleep. And good sleep is of course essential to physical and mental health and wellbeing.
But how bad is blue light from digital devices, really?
The truth is, we don’t know exactly how much damage is done by the blue light emitted by digital devices. The blue light exposure from screens is less than that of the sun and considered safe for short-term use. The real concern, however, is with prolonged blue light exposure, as well as the relative proximity to the screen. There is simply insufficient research to conclude exactly how much damage blue light is doing to us or our children over time.
What we do know for sure is that blue light from screens can be very disruptive to sleep cycles, which can in turn lead to or aggravate various physical and mental health concerns. Studies have also linked night time blue light exposure to depression, diabetes, obesity and cardiovascular disease.
Many thanks to the following sources:
https://mhanational.org/blog/how-blue-light-affects-mental-health
https://www.allaboutvision.com/cvs/blue-light.htm
https://www.allaboutvision.com/cvs/children-computer-vision-syndrome.htm
https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
https://www.jahonline.org/article/S1054-139X%2814%2900324-3/fulltext