Eye fatigue, eye strain, tired eyes—Computer Vision Syndrome (CVS) affects up to 90% of office workers according to Vision Source, an independent optometrist network in the U.S.

If you look at a computer monitor all day for work and experience any of the following symptoms, digital eye strain is the likely culprit.

Sore, tired, burning or itchy eyes;

Eyes that are too dry or too watery;

Blurred vision or double vision;

Soreness in upper back, neck, shoulders;

Vampire-like sensitivity to light;

Feeling that you can’t keep your eyes open.

What can you do about tired eyes when you have a screen heavy job? I talked to several optometrists specializing in CVS to draw up a course of action. Topics include:

The 20 20 20 rule of focusing

Proper viewing distance, angles, and lighting environment

How different types of monitors affect eye strain

Protective eyewear and reminder applications

Now let’s get started finding relief for those tired eyes.

Tired eyes come from prolonged close-focusing and bad blinking

“Vision and computers go together like oil and water,” says optometrist Dave Kading, owner of Specialty Eyecare Group in Seattle. This is due to the way the eye muscles work.

Ocular muscles contract and engage for viewing objects close up, and relax when looking into the distance. It is human nature to hone in on what stimulates the brain; this is why it is easy to ignore eye fatigue symptoms during the work day. “Our focusing system can get very locked in place,” Dr. Kading explains. If you stare at a screen all day, he says, “it’s like standing on one leg with your knee bent in a squat position—I don’t care who you are, you will fatigue with time.”

Worse, we blink 50-75% less when engaged in screen work. Use a web cam to record yourself looking at a computer monitor. “You’d be surprised how horrible your blinking is,” he says, noting in particular the tendency to half-blink when gazing at a screen. “Our eyes are not able to release the proper oil components into the tear film, and like a car engine, this can lead to friction and irritation.”

Abide by the 20 20 20 rule—and blink hard

Almost all eye doctors recommend using the 20 20 20 rule—for every 20 minutes of work, look at something 20 feet away for 20 seconds. The break frees the eyes from the locked position and lets them relax.

Image credit: American Optometric Association. (aoa.org)

During the break, slow and mindful blinking of the eyes helps. “Blink hard nine times in a row before or after gazing into the distance,” recommends optometrist Bryan Holman, an Alabama-based specialist. “It helps the oil glands and stabilizes tear production.”

The real trick is remembering to do 20 20 20 during the work day. Applications can provide assistance; a few popular choices are:

Awareness – plays the sound of a Tibetan singing bowl to mark break times.

ProtectYourVision – a browser-based reminder system that you can customize alerts.

TimeOut – configurable reminder utility for OSX and iOS.

Monitor positioning for the best light

Position the center of your monitor 4-5 inches below eye level, at about an arm’s distance away, advises optometrist Shazeen Ali, an Austin, Texas-based practitioner.

The lighting around your monitor is just as critical. “Excessive bright light either from overhead lighting or sunlight from windows can also cause eyestrain,” she says. “Position your computer screen to minimize glare from these sources and avoid using high-intensity ambient lighting.”

Natural light is the best for eye health, but orient yourself so the windows shine perpendicular to the angle that you view the computer monitor.

Florescent overhead lighting is notorious for monitor glare, so use it sparingly if possible.

At night, a full-sized floor lamp is a better option than a spotlight desk lamp. Placing an inexpensive LED bias lighting strip behind a monitor reduces eye strain when working in a dark room.

Adjustable monitor arms and monitor risers accommodate finding the proper angle for safe viewing.

There are applications that automatically manipulate screen lighting so it fits best with the time or day other lighting factors. A few good ones to try out:

EyePro – Android-based digital filtering system

Nocturne – OSX application that switches white backgrounds to black at night

f.lux – automatically adapts display warmth to the time of day

Special computer eyewear to reduce blue light

Discomfort from tired eyes pales in comparison to the long term risks posed by excessive screen time. Certain kinds of light can harm the eyes if overexposed. The blue-violet and ultraviolet wavelengths that electronic devices emit can potentially cause cataracts and retinal disease.

For more severe cases of eyestrain, each doctor recommends special computer eyewear with amber-tinted lenses that guard eyes from bad light wavelengths.

LCD screens and flicker-free technology

Doctors recommend using flat-paneled LCD screens which usually have an anti-reflective surface and tend not to flicker like old CRT monitors. “Even when flicker is imperceptible, it still can contribute to eye strain and fatigue during computer work,” Dr. Ali warns. “When choosing a new flat panel display, select a screen with the highest resolution possible and relatively large screen display size.”

This comes with a caveat—obviously a huge 4K monitor does not suit basic office use. For eye health, you will be fine with a computer monitor over 19 inches corner-to-corner, and capable of Full HD resolution (1920 x 1080 pixels).

Be mindful of LED dimming features and flickering

With LED backlit computer monitors, you will find research that shows screen dimming features can induce detectable flicker. This occurs more often with monitors that use pulse width modulation (PWM) for brightness control. To address this, LED monitor manufacturers have developed flicker free technology with buzzword-sounding names that vary by vendor.

A few examples: ASUS Commercial Series uses a proprietary technology called ASUS EyeCare. Certain ViewSonic LED monitors use a different dimming technology called direct current (DC) to control flicker. BenQ monitors with ZeroFlickerTM achieve similar ends.

Check the product pages in the computer monitor store for features like the ones listed above.

Final Thoughts

A combination of behavioral techniques and simple applications and tools can help reduce tired eyes from prolonged computer monitor usage—let me know in the comments what works for your eye fatigue.