Don't let this happen to you. (elen King/Corbis RM Stills/Getty Images)
It's 2:00 p.m. and you have a few more hours until the end of your workday.
Your eyes sting, your vision is getting blurry and your head hurts. The computer screen that you've been staring at for the past six hours seems so bright that you want to shut your eyes.
Sound familiar? We'd bet yes.
Piotr Le, a Georgetown University grad student, thinks so, too. He used to work in consulting — and that meant staring at a computer screen for 12 or more hours every workday.
"Partially I left because of the physical deterioration of my body," Le says. "A lot of eye rubbing. That's why my prescription got worse. I would wake up with neck pain and back pain."
Depending on whether you consult an optometrist or an ophthalmologist, you might get different answers on what ails you. Is it computer vision syndrome? Is it digital eyestrain? Is it just dry eyes and some eyestrain?
The most common definition is given by the American Optometric Association, which coined computer vision syndrome and digital eyestrain as a group of vision-related problems from viewing digital screens for a long time.
The American Academy of Ophthalmology labels it digital-related eyestrain. The group emphasizes that extended reading and writing can also strain the eyes.
Neither computer vision syndrome nor digital eyestrain is an official medical condition. They are more of a collection of symptoms that sometimes include headache, neck and shoulder pain.
"Classification schemes do take time to develop, and so it may not have crept into medical coding," says Dr. Michael X. Repka, a Johns Hopkins ophthalmologist and clinical spokesman for the American Academy of Ophthalmology.
Repka says in the past these symptoms would be lumped under asthenopia, a condition that encompasses eye fatigue, ache around the eyes, blurred vision and headache. Computer vision syndrome, he says, is considered to be under asthenopia in the ICD-10 medical coding system.
"Computer vision syndrome ... is not a recognized medical entity," says James Sheedy, a professor of optometry at Pacific University and head of the Vision Ergonomics Research Laboratory. "A medical diagnosis is a condition where the anatomy or physiology isn't functioning properly. There are several different medical diagnoses that could be the cause of what is commonly called computer vision syndrome. There are different names put on it. Those are really names to create a black box where you put everything into ... but it's really the same thing."
The fact that these symptoms are common is self-evident. Optometrists and ophthalmologists agree that many patients walk into their offices with these complaints. But is there enough evidence to upgrade their diagnostic status?
"I think research is coming out now that this really is a different condition," says Mark Rosenfield, a professor at SUNY College of Optometry. "There is something about these screens that is different from paper and so we're trying to figure out what aspects of screens is it that is causing problems. People didn't look at paper for that length of time [that] people are looking at screens, so I think that could be a factor too — the fact that people are looking at these things for such long periods of time."
So why do our digital screens cause us so much trouble?
"We're not really designed to do full-time near work; we're designed to do part-time near work, and so to the extent that we have to do so much near work our eyes are in tension virtually all the time," says Steve Loomis, president of the American Optometric Association. "The average worker spends seven hours a day on some digital device. ... I'm among them and so what we know is that that means that the muscles in the eye are in a state of tension."
In a review of studies for the journal Ophthalmic & Physiological Optics, Rosenfield found that we have more incomplete blinks during computer operations, which reduces the volume of tears in our eyes. Too few tears causes irritation and a burning sensation in the eyes.
A more recent review of the syndrome in IOS Press lists other factors: glare from windows, overhead lights and the computer. Also, the particulars of how your computer or digital devices are arranged, including the height and viewing distance of the device from our eyes. We also tend to hold hand-held devices closer to our eyes than we should.
"The eyes work best we know by looking down about 15 degrees in most desktop computer situations. This means that the top of the computer screen displays should be level with the eyes," Sheedy says. "If it's higher or lower than that the person tends to tilt the head back or forward and now they have an imbalance and this creates muscular tension and it can give them a neck ache."
The evidence doesn't suggest these symptoms are permanent. They can be alleviated by changing our workplace habits. Anti-glare screen filters and eyedrops may help some. Optometrists say that some people who use reading glasses may benefit from trying glasses with a different focal length for computer work.
One of the most commonly cited — and cheapest — things to do is just to give your eyes a rest. Follow the 20-20-20 rule: Every 20 minutes, look at something at least 20 feet away for 20 seconds.
Grad student Le now stares at his computer only four to six hours a day. He says he still gets occasional neck pain from looking down at his laptop. And the white backgrounds of PDFs and Word documents still bother his eyes some. He's also trying software to make the tone of his screen warmer.
But his go-to move is taking a break. "I close my eyes and look at the skyline," he says, "or something that is not bright."
Copyright 2016 NPR. To see more, visit http://www.npr.org/.
Get the best of KQED’s science coverage in your inbox weekly.