Remember what your parents told you as a child? “Don’t sit so close to the Television, you’ll go blind.”
While that may not necessarily be true researchers have found that blue light near you can affect your sleep and potentially cause disease.
WHAT IS BLUE LIGHT?
Not all colors of light were created equal or have the same effect. Blue wavelengths are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night.
And the expanse of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown.
Until the advent of artificial lighting, the sun was the major source of lighting, and people spent their evenings in (relative) darkness.
Now, in much of the world, evenings are illuminated, and we take our easy access to all those lumens pretty much for granted.
I'M NOT SLEEPY
Everyone has slightly different circadian rhythms. The average length is 24 and one-quarter hours. The circadian rhythm of people who stay up late is slightly longer. The rhythms of earlier birds fall short of 24 hours.
Dr. Charles Czeisler of Harvard Medical School showed, in 1981, that daylight keeps a person’s internal clock aligned with the environment.
EXPOSURE TO BLUE LIGHT IS BAD
Some studies suggest a link between exposure to light at night, such as working the night shift, to some types of cancer, diabetes, heart disease, and obesity.
We do know that exposure to light suppresses the secretion of melatonin, a hormone that influences circadian rhythms, and there’s some experimental evidence (it’s very preliminary) that lower melatonin levels might explain the association with cancer.
BLUE LIGHT IMPACT
While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness.
The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
PROTECT YOURSELF FROM BLUE LIGHT
Use dim red lights for night lights. Red light has the least power to shift circadian rhythm and suppress melatonin.
Use special eyeglasses to help reduce risk
Avoid looking at bright screens beginning two to three hours before bed.
If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses .
Expose yourself to lots of bright light during the day, which will boost your ability to sleep at night.