Everything you need to know about Digital Eye Strain in 2022: the 20 20 20 Rule and other ergonomic concerns

March 1, 2023

In the United States, two out of three people report digital eye strain (DES), a series of unpleasant symptoms related to frequent use of computer monitors, tablet computers, or phone screens. While DES isn’t as simple to diagnose or treat as, for instance, strep throat, this collection of symptoms can interfere with work hours and comfort. We can work together to relieve the pain of eye strain and prevent musculoskeletal injury. 

Ergonomics is the study of making a workspace fit the needs of an individual body for safety, productivity, and comfort. DES is considered an ergonomic issue because it poses risks to your musculoskeletal system. Musculoskeletal disorders (MDSs) are injuries or disorders of the muscles, nerves, tendons, joints, cartilage, and spinal discs (CDC). Listen to your body and exert your influence on your environment. While your job may not be very physically demanding, being stationary all day can still take a toll on your body.

Even though the causes of eye strain aren’t always strictly digital, we can call these symptoms DES or Computer Vision Syndrome (CVS). This group of problems with our eyes springs from maladjustments of our digital-age workspace and habits. In other words, it’s not just the screen, it’s how we’re sitting in front of it, how it’s spaced, how it’s lit, and our personal sensitivities to these things. 

Understanding the hazards of this 21st-century lifestyle and avoiding pain and work time lost from an MSD means understanding the needs of your own body. In this, and all medical issues, always consult your physician, optometrist, or ophthalmologist. Corrective lenses, when necessary, are an essential piece of personal protective equipment (PPE).

Consequences of Eye Strain

The body of symptoms called “Digital Eye Strain” include:

  • Blurred vision
  • Difficulty focusing
  • Eye irritation or burning
  • Dry eye
  • Visual fatigue
  • Headaches
  • photosensitivity

Understandably, office employees could find any one of these symptoms debilitating. Fortunately, scientists have been studying computer use for more than twenty years, and so far, there is no evidence that DES causes permanent eye damage.That’s reason to hope! Working at a desk on a computer, in itself, won’t make you blind. More than 50% of all employees who experience this pain, fatigue, dry or red eyes, or blurred vision can take a deep breath. We have some solutions. Keep reading!

If you’re looking for a universally applicable solution, it doesn’t exist yet. OSHA repealed its ergonomic standards in 2001 because human bodies and their work are too varied (or not!) for universal standards to keep us safe from MSDs. Everyone’s body is different, and will have different standards and requirements. Making your workplace more ergonomic can be as simple as raising your chair a few inches, or adding lumbar support. These concerns can sound silly, as if we’re only trying to make ourselves comfortable, but when the pain begins and your productivity is crippled, things get real.

Digital Hazard: Understanding the Problem of Eyes and Computers

Strain comes from over or underusing a muscle. Don’t forget that a muscle controls the light reception inside your eye: the iris is a sphincter muscle that opens or closes in reaction to the amount of light you need, and can become fatigued if there’s too much or too little light, or if the contrast is too little or great.

Muscles around the eye also protect the eye from overdrying, wind, dust, and other dangerous materials that can damage the eye’s surface or interior. Those blinking and squinting muscles can also contribute to the body of symptoms we call DES if they become fatigued, or are simply not functioning adequately in your work environment. 

Why do computers cause eye strain? The National Institutes of Health stated in 2008 that when considering light and screens, brightness, resolution, glare, and quality are the CVS culprits. All of these things can be adjusted or compensated for to make your workspace more eye-friendly.

Don’t Blink?

Early studies observed that people tend to blink less while using screens than while doing analog tasks. A quick internet search will bring up blogs and commercial sites that mention slower blink rates as a digital-age eye hazard that can cause dryness and eye pain.

However, this study from 2014 corrected a lack of proper controls from those earlier studies. The researchers found that when tasks needed the same amount of concentration, whether on a screen or not, a person’s blink rate slowed. A person might blink less while doing needlepoint or writing up lab notes, so it’s not the light from the screen that interferes with blinking. The cognitive load of your task – the amount of concentration – makes the difference. 

You can’t stop your brain from thinking at work, so let’s focus on other ergonomic factors that cause eye strain when we work with screens: 

  • the distance and position of the screen, 
  • lighting conditions, and 
  • inadequate corrective lenses.

Concentration isn’t the only culprit. Something as simple as an increase in physical or emotional stress can also lead to changes in facial expressions which can contribute to tension in the shoulders and neck. As an experiment, clench your jaw. Can you feel which muscles flex? Imagine clenching your jaw unconsciously for hours at a time. That’s strain. And jaw clenching is only one of many possible expressions of stress that can cause strain.

Additionally, increased cortisol levels from long-term stress can, according to this study from 2018, cause permanent eye damage if the stress and impairment become a vicious cycle. The next two sections will address how to avoid that dangerous spiral. Begin by reminding yourself that you can find relief from this pain and irritation. You can feel better.

Prevent Eye Strain: Occupational Health and Safety

Additionally, increased cortisol levels from long-term stress can, according to this study from 2018, cause permanent eye damage if the stress and impairment become a vicious cycle. These next two sections will address how to avoid that dangerous spiral. Begin by reminding yourself that you can find relief from this pain and irritation. You can feel better.

Look out 

Check your environment for light sources and quality. 

  • Is your office small and dark? 
  • Are there windows or skylights and are they shaded? 
  • Do the lightbulbs produce warm or cold light? 
  • On your computer screen, if you change the contrast levels, can you read more easily? 
  • Is the refresh rate too slow?
  • Is the resolution too low? 
  • Is there a glare? 

Take the time to find, learn, and adjust these settings. Explore “dark mode.” 

Look at your desk: 

  • Do you face toward or away from the strongest light source?  
  • Are you under an air conditioning vent or fan that could cause over-drying? 

Reach out

  • Is your computer screen about an arm’s length away from you?

If that feels too far, definitely consult an optician! Larger monitors should sit even further away. 

If the desk or monitors are too high, constantly looking up can strain your neck and back.

Look in

  • How’s your posture? 

Pay attention to your facial muscles (cheeks, jaw, eyebrows), shoulders, and back. 

  • Are you clenching your jaw? 

Stand and stretch. Look at something that makes you smile. It’s always best to start healthy habits before the bad ones start causing problems. 

  • Are you prone to other things that can cause photophobia or light sensitivity?

Do you get silent migraines, for example? A qualified doctor can diagnose and prescribe solutions.

You should also listen to your physician and avoid screens if you have had a recent concussion, lasik surgery, or other eye trauma! 

20-20-20 Rule to Reduce Eye Strain

Many of the environmental factors above can be adjusted easily, but you may still struggle with symptoms of eye strain (listed above). A commonly shared way to be kind to your eyes is the 20-20-20 Rule. This simple and effective trick, shared around offices and business conferences since the nineties, can bring immediate relief. Every twenty minutes, look up from your screen at something at least twenty feet away for about twenty seconds. Easy to remember, isn’t it?

Why 20 seconds? Why twenty feet? Why Twenty minutes? Don’t stress about precise measurements. Just look up and into the middle distance, or out a window, until you can feel your gaze relax. This brief rest will refresh your eye muscles. Take the opportunity in those moments to resume normal blinking patterns if you’ve been concentrating. If you’re at a computer, try a Pomodoro timer, or simple countdown timer to remind you to switch tasks or look up. That simple variety brings positive results and helps you be kind to your eyes

Who wrote the 20-20-20 rule? 

Brian Chou, OD, FAAO, FSLS, researched this question and found a concrete answer. To summarize his findings from the Optometry Times: Jeffrey Anshel, OD, FAAO invented the rule in 1991. Anshel was an optometrist, author, and lecturer in California, and he definitely regrets not copyrighting the phrase. You can read a more complete list of his credentials here.

Where does the 20-20-20 rule come from? 

Dr. Anshel invented the rule as a rhetorically effective way to remind corporate employees to give their eyes a break while still remaining productive at work. “The general rule at the time was to take a 15-minute break every two hours” Chou records from his conversation with Dr. Anshel, but shorter, more frequent breaks are necessary to prevent MSDs. Every two hours wasn’t often enough.

What evidence backs it up?

Both doctors admit that no peer-reviewed studies exist yet to support the benefits of the rule. They note that this trick won’t “stop or reverse myopia development or progression,” which likely stem from more complex causes. Optometrists and workplace safety experts still recommend the 20-20-20 rule to relieve DES, even if it doesn’t halt myopia. Looking up and out a window is still effective against all of the symptoms and loss of productivity from overtaxing your eyes in the office. 

Understanding the origins of this well-established practice can help us understand and implement it as a strategy, rather than a stressor. 

  • Stare out the window for a minute. 
  • Take thirty seconds to plan your dinner. 
  • Remind yourself to stand up, rest, or stretch frequently. 

Frequent, short breaks can improve your productivity and quality of life. You deserve this care, and more!

Blue Light Glasses?

Another common remedy for eye strain, recommended in blogs around the internet, is blue light glasses. The theory behind this remedy is that blue light causes DES/CVS. Blue light is the frequency of light from the sun that causes alertness. Relatedly, the CDC and NIOSH recognize that blue light, of the entire light spectrum, has the most impact on circadian rhythms, and should be restricted in bedrooms and at bedtime. But blue light frequencies can help you feel awake and energized. It’s possible that not filtering blue light, especially from sunlight, could help relieve fatigue during the day.

So, do blue light glasses work? Well, that depends on what you want them to do. People who sell eyeglasses will tell you that blue light and glare are the only culprits behind CVS. They might be onto something. Be aware, though, that blue light glasses are NOT prescription computer glasses. A very small study on medical residents in 2019 found that blue light filtration may help alleviate symptoms of CVS. Those who conducted this study admit that more research is necessary before claiming anything more conclusive. It might be nice to hear more from scientists instead of salespeople on the subject.

Lessons Learned

DES, CVS, and MSDs affect employee productivity in noticeable amounts every year, and it’s not just in your eyes. The muscles in your back, shoulders, neck, and face are part of the problem, the warning system, and the solution. Listen when your body speaks to you: especially when it expresses suffering. 

Arrange your workspace for comfort and efficiency, with your eyes in mind. Care for yourself by taking frequent breaks to stretch and look away from your screens. Prioritize your eyes. They can make life better right now and in the future.

Whether at a new job or nearing retirement, kindness to your eyes can make a noticeable difference. Whether you already experience regular soreness, discomfort, or if you’re just a little fatigued, paying attention can prevent these sensations from getting worse. When you take control of your computer work environment and make it eye-friendly, you can enjoy your work more, relieve symptoms, and avoid eye strain altogether.