In a world filled with screens, from smartphones to computer monitors, TVs, tablets, and digital books, our eyes are exposed to the rainbow of digital light daily, but no other color gets quite as much attention as blue light.
“There was some research years ago that suggested that blue light coming from screens would damage the retina and accelerate macular degeneration,” said Stephanie Handal, OD, an optometrist with the Robert Cizik Eye Clinic – Texas Medical Center. “But there were some flaws in that research, and we now know this isn’t the case.”
What is blue light?
Blue light is part of the visible light spectrum. Light is measured in wavelengths; the average human can see light from 380 nanometers to about 700 nanometers. Each wavelength within this spectrum produces a different color.
“We hear different sounds because wavelengths produce different pitches. The same is true for color. Different wavelengths also produce different colors,” said Handal.
As bookends of the rainbow, red has the longest wavelength, and violet has the shortest.
“The reason we see rainbows in the same color pattern every time is because of wavelengths,” said Handal.
What the human brain sees as the color blue is light in the 450-500 nanometer range. Sunlight is the most powerful source of blue light.
Blue light coming from screens
Blue light emits the highest energy and therefore has the greatest potential for harm, but there isn’t enough blue light coming from digital screens like smartphones and computer monitors to damage vision.
“While blue light can be damaging, we simply don’t get enough of it from our screens to cause harm,” said Handal. “We get much more exposure to it from a short time in the sunlight than from hours on our screens.”
Blue light’s impact on sleep
Our eyes also help regulate the body’s natural circadian rhythm. Specific cells in the retina tell the body when it should be awake and when to shut down for sleep. Blue light is an important factor that tells your body to be alert and awake.
“By blocking blue light, some patients may feel it’s easier to fall asleep,” said Handal.
Self-help options
For those who prefer taking precautions, you can reduce the blue light on your smartphone without purchasing glasses.
The setting is called “Night Shift.” Once you turn it on, your phone automatically adjusts the light colors you see at night to a more yellow hue.
“For patients who feel any improvement in their dry eye, screen fatigue, or sleep patterns by wearing blue-light-blocking glasses, they are worth every penny,” said Handal. “But patients can rest easier knowing that the blue light from our screens, with or without blue-light-blocking glasses, will not damage our eyes.”
Blue light is part of the spectrum of light we see every day. While technology exists to reduce how much we absorb, research shows it is unnecessary to block blue light from the average daily use of digital screens.
