By Christine Cioppa
It’s been drilled into our heads that UV light is bad for our eyes, so we wear sunglasses outdoors. Now, we’re hearing the same about computer blue light. Blue light does, in fact, affect vision, but what’s fact and what’s myth?
FACT OR MYTH?
Blue light affects vision
Fact. But not in the way you think. Blue light is a short-wave light that our eyes perceive and transmit into images in our brain. It is a naturally occurring light from the sun and an artificial light from electronic devices and fluorescent bulbs, including compact fluorescent bulbs.
Hours and hours spent on computers, tablets and cellphones can make eyes work harder and cause eye strain. “We know that blue light, from a computer screen or tablet or cell phone, makes it harder to focus,” said Adam Gordon, O.D., M.P.H., F.A.A.O., clinical associate professor of Optometry at UAB School of Optometry. Compared to an image in a printed book or page, Gordon says “a pixilated electronic image is definitely harder for the eyes to maintain a clear, sharp, consistent focus.” Because of this, “blue light can contribute to eye strain or eye fatigue,” he says.
THE FIX: Gordon says follow the 20/20/20 rule. “It means after 20 minutes of continuously viewing the computer screen, it’s best to look away from the screen and look at something at about 20 feet away, off in the distance, for about 20 seconds.” He suggests focusing out the window, down the hallway or on some distant object, which he says will give the focusing mechanism in the eyes a break before you go back to reading or studying. “Also there are OTC lubricating drops or moisturizing drops that can relieve some of the dryness associated with staring at a computer.”
Blue light affects sleep
Fact. Blue light affects circadian rhythm or the body’s sleep-wake cycle. “It does this by inhibiting the melatonin production, that normally occurs in the brain, which helps us get drowsy and fall asleep at our bedtime,” explains Gordon.
“If someone is staring at their cellphone, tablet or computer, or studying for exams extensively for many hours in the night, then tries to go to bed, there may be an effect from the excessive blue light exposure,” says Gordon. “It may make it harder to fall asleep … or even get restful beneficial sleep that you’ll need.”
THE FIX: Use computer screens or eyeglass lenses that minimize or block blue light. Also, shift Apple devices to the nightshift setting.
“There are screen protectors that you can buy that are fairly inexpensive for most computer monitors, tablets, and just about any kind of cell phone. What it does is block some of the blue short wavelengths coming out of the device.”
Adjusting your electronic settings may help too. “In the latest version of the Apple operating system, especially with the cell phones, there is this nightshift setting. This setting on Apple devices basically shifts the color spectrum from the normal one to more colors in the yellow, orange, red end of the spectrum. The idea is to do this at night or in the evening after dinner, before bedtime,” says Gordon.
Blue Light Causes Macular Degeneration
Likely False. There’s been lots of controversy about the link to this eye disease and blue light, but Dr. Gordon has not seen evidence of this. “Just based on the fact that the exposure from outdoor sunlight is so many more times intense than anything coming from a computer, or a cell phone or a fluorescent light bulb, in my opinion, it is unlikely that there is really any threat of physical damage to the eye, including macular degeneration.”
Read more about blue light and vision at:
http://www.aao.org/eyenet/article/back-forth-controversy-on-blue-filtering-iols
https://www.uab.edu/news/youcanuse/item/7258-debunking-digital-eyestrain-and-blue-light-myths
