We’ve all seen it, heard it, or even said it at some point in our careers—the 20-20-20 rule. This catchy phrase goes that for every 20 minutes of performing a near task, we should give our eyes a 20-second break and look at an object 20 feet away.1
The goal here is to combat the symptoms associated with the buzzword “digital eye strain.” On the surface this reminder is simple, easy to remember, and can be applied to nearly all of us, but let’s dig a little deeper.
Together, we’ll explore some of the ins and outs of this approach to see where it came from, its validity, and uncover if it is an adequate way to address our patient's visual complaints today.
Overview of digital eye strain
Digital eye strain (DES), or what was previously termed computer vision syndrome (CVS), are terms that encompass the myriad symptoms patients may experience during or after screen use. These complaints can include eye irritation, discomfort, strain, asthenopia, headaches, blurry or unstable vision, and others.2
The American Optometric Association states that the average American uses a computer for 7 hours during their work day.2 As technology has become more popular and mobile over the years, terminology has changed away from CVS to the newer, more inclusive DES to not limit itself to computer usage specifically. That means this 7-hour figure can quickly increase when we also account for the use of televisions, tablets, e-readers, or phones.
It is thought that the symptoms listed above arise due to the behaviors of our eyes when focusing at near targets. People have been connecting the dots between the demands and stressors we place on our eyes and bodies when using computers since the 1980s.3
One report estimates that nearly 33% of people suffer from DES symptoms.4 That report goes on to say that in groups that expose themselves to longer durations of screen usage, this figure can rise to about 50%.4
The impact of screen versus page on digital eye strain
It’s worth mentioning there are brightness, contrast, glare, and clarity differences between device screens and paper or other print materials. However, I would argue that whether it’s a computer screen, a book, a phone, or a slit lamp, our eyes are carrying out similar tasks. They must properly accommodate to bring the near object into focus.
At the same time, they need to maintain proper convergence and, in some cases, perform saccades and/or pursuits accurately to keep up with visual demands. Finally, during prolonged periods of near focus, our brain and eyes work to obtain as much information as possible, and our blinking rate goes down drastically.5
Couple all of these factors together and our eyes are working very hard at a task that appears so simple on its face. However, once we start to extend the time we demand our eyes to perform these tasks, DES symptoms can begin to increase.
Breaking down the 20-20-20 rule
In an Optometry Times article, Brian Chou, OD, FAAO, FSLS, works to track down the origins of the 20-20-20 rule. His search points him in the direction of Jeffrey Anshel, OD, FAAO, as the original creator of the popular reminder during the 1990s.6
To summarize, the initial idea was derived from recommendations that more frequent, though short, breaks were more helpful in reducing eye strain when compared to longer breaks spread less often through the day.
The rule makes a lot of sense. If all of the symptoms of DES arise from looking at near targets, we should look at distant targets to reduce the load on our visual system. Our eye’s accommodation should relax when looking back to the distance. Likewise, the convergence of our eyes should lessen with looking far away and our blink rate should return to baseline.
If only things were that simple, we would all take to the 20-20-20 rule and be on our merry way with comfortable vision and happy eyes.
Why the 20-20-20 rule is ineffective
For better or worse, in a world of production and deadlines, time is money. Two out of three components of the 20-20-20 rule have to do with time. If we consider the previously mentioned 7 hours spent on a computer during a work day, we’re asking the population to effectively take 21 breaks during their day to consider their eyes for 7 minutes total.
This may not seem like a big ask, and yet, in one study, only 34% of participants practiced the 20-20-20 rule at all.7 Also, the majority of those partaking did so only occasionally. Similarly, they were more likely to perform the regimen if they were already experiencing DES symptoms. This may insinuate a lack of preventative or prophylactic use of this routine.
Dealing with limited data
Though data is limited, there have been a few studies that look at the efficacy or validity of the 20-20-20 rule as it relates to DES symptoms. Overall, there is not significant evidence to suggest that practicing the rule reduces symptoms.7,8
However, looking at the study by Datta, there were associations between those who had symptoms and those who were practicing the rule. This may suggest that patients that suffer from DES are looking for answers, and are more motivated to follow routines suggested to them. These recommendations still need to be expanded on or revised to offer long-term symptom relief.
Digital eye strain as a multifactorial disorder
Because the 20-20-20 recommendation relies on multiple systems working in unison and cooperating properly, it could be argued that DES is a multifactorial disorder. For starters, in order for a person to focus up close, they have to have the necessary accommodative amplitude available. Not only that, but when considering how long the task will take, they also must sustain that accommodation for an extended duration.
When the 20-minute timer rings and our patient looks at a target in the distance, they’re now asking those accommodative muscles to relax. However, these muscles may have issues where they cramp or spasm and have a difficult time releasing their contraction. These patients would remain in a state of near focus or “leading” their point of focus in front of their target of choice.
As accommodation and convergence are tightly related within our visual system, if the patient is experiencing accommodative spasm, their vergence system is also combating an eso posture to remain aligned with their target’s position. This can also place an unwanted strain on the extraocular muscles for patients.
When the ciliary body or extraocular muscles remain strained or contracted, headaches can manifest in, behind, or around the eyes. Objects or words may become blurry if our focus is not properly placed on the correct visual plane.
The reduced blink rates associated with device use can also lead to changes of the ocular surface.5 Beyond blink rate, it’s been demonstrated that digital screens are also associated with incomplete eyelid blinks.9 When blinks are slowed or done partially, the tear film becomes unstable and begins to evaporate. This can lead to blurry, inconsistent vision and dryness issues.
The blink forces of the lid also work to naturally express oil secretions from the eye’s meibomian glands, and these oils may begin to stagnate if blink rates are greatly decreased for extended periods of time. We know that ocular surface disease is a cycle and will continue to create issues that invigorate themselves, as demonstrated by the Dry Eye Workshop (DEWS) II study.8 Make no mistake that proper visual hygiene and device habits are important pillars in how we manage the surface of the eye.
4 steps to improving visual hygiene
As with any field of healthcare, we’re always “looking” to improve the lives of our patients. Though definitely not as catchy of a name, I believe our profession needs to coordinate a few Golden Rules of Visual Hygiene (calling dibs on the name now) to offer our patients. These rules can better reflect the demands we face in our digital world and what we know of the visual system.
Here are a few beginning suggestions.
1. Educate patients early on digital eye strain.
When it comes to discussing routines and instilling healthcare habits into patients, a terrific example is the dental model. Every person learns from a young age to brush their teeth twice every day, floss daily, and the importance of mouthwash use. We’re even given the necessary resources at those appointments to keep up our oral hygiene.
Why should eyecare be that different? We have the resources at our disposal to have materials for patients that educate them on the benefits of visual hygiene and can give samples and coupons of our recommended products when available.
We can take it one step further by utilizing platforms such as Dry Eye Rescue, Peeq Pro, or Myze to extend reputable and preferred products to patients well after the exam. Discussing these recommendations at comprehensive eye exams, especially for our pediatric population, is important to set patients up for future success.
2. Perfect the prescription.
Our vision can only be as good as we allow it to be. Meaning, an accurate prescription is needed in order to fully relax accommodation at a distance. This would allow the available accommodative amplitude to be utilized to focus on near objects and place less accommodative strain on the visual system.
Whether for contacts or spectacles, lens design plays an important part here. While some patients may only need a single vision spectacle correction, we may consider a separate computer-tailored prescription for others.
Some patients struggle to find their “computer distance” in a progressive lens design. They may be excellent candidates for a single-vision computer prescription as this could provide more comfortable, stable vision during prolonged device usage. These task-specific lenses may also be beneficial if someone has multiple displays or screens that are not below eye level as is usually customary.
Still, other patients may be aided with designs such as Eyezen designs that aim to reduce accommodative demands when looking at near targets, but with less power than standard progressive lenses. This can provide a little help to the visual system during extended computer activities.
These lenses also carry additional benefits, such as blue-light filtering technology. Some also have enlarged or multiple “optical centers” to provide more clarity throughout the lens itself.
Contact lens considerations
Similarly, in the realm of contact lenses, patients may experience blurry vision if their lenses are unstable during wear, are drying out, or if their prescription is not tuned in properly for device viewing (more in the cases of multifocal or monovision correction). Choosing lenses with adequate hydration and visual performance will set the stage for comfortable vision during the day.
Lenses such as Johnson & Johnson’s Acuvue Oasys MAX 1-Day lineup have OptiBlue light filtering to reduce blue-light penetration and TearStable technology to aid tear film stability and reduce tear evaporation during wear.11
Alcon lenses like the Total 30 lineup and the Dailies Total 1 for Astigmatism and Dailies Total 1 Multifocal lenses all offer their water gradient technology to provide lens hydration and surface wettability along with some blue light absorption.12,13
Still another manufacturer, CooperVision, offers their Energys family of Biofinity Energys and MyDay Energys lenses. These contacts, while only in spherical correction at this time, utilize DigitalBoost optics to provide a +0.30D aspheric change in power to reduce eye fatigue and accommodative demand.14
It’s important to note here that there remains inconclusive evidence that blue-light filtering technology improves or reduces symptoms of DES or visual fatigue.9 Some patients still anecdotally feel subjective improvements, although it is difficult to distinguish if this is significant or related to placebo effects.
3. Delve deep into DES.
While providing optical recommendations can definitely have its benefits, DES is a multifactorial issue that requires further assessment. We can dig a little further regarding patients’ workstation setups, the number and location of monitor displays, or any current visual hygiene practices patients have.
Within patient encounters and intake questionnaires, simple questions can be asked about the amount of screen time our patients have during the day. One study states that the Digital Eye Strain Questionnaire (DESQ) proved to be a reliable screener for patients exhibiting DES symptoms.15
Learning all of this information not only provides us with a baseline of what our patients are currently experiencing, but also allows us to tailor our recommendations and treatment plan to the person in the chair. Similarly, some patients may begin to elicit complaints or DES issues they had not considered mentioning before.
When assessing the ocular surface, careful attention can be paid to the tears, eyelids, and the blink. These features can alert us to ocular surface disease (OSD) or issues that will concurrently need to be addressed.
Likewise, our comprehensive examinations can allow us to evaluate patients for accommodative or binocular vision deficits. Full evaluation and even therapy or treatment for these disorders may require more specialty care.
Nonetheless, primary care optometrists are fully capable of performing myriad screening tests, especially on those complaining of DES-like symptoms. These may include NRA/PRA testing, the amplitude of accommodation, refraction, cover test, and near-point of convergence.
4. Explore ergonomics.
Moving from the exam room back to the patient’s workspace may also require some adjustments. The ergonomics of their desk and monitor(s) may require some adjustments to optimize for proper viewing angles.
Lighting considerations may need to be made if screen reflections are an issue or to place less strain on the eyes from overall brightness. The proximity of overhead fans or air vents may also need to be addressed when implementing a comprehensive DES treatment plan.
If dry eye or ocular surface recommendations were made during their exam, patients will still need to put these new habits in place. For most people, starting new routines or creating new habits can be quite difficult.
It can be helpful to place eye hygiene reminders around things we’re already doing. Placing eye drops on the desk below a monitor can make it easy to glance at during the day and serve as a reminder to instill artificial tears or to take a blink-break. Likewise, performing eyelid hygiene once or twice a day can be made easier if it’s done at the same time someone brushes their teeth or showers.
Task-based timers that follow the Pomodoro technique of bursts of focus around 15 to 30 minutes followed by a few-minute break are ideal representations of the 20-20-20 rule of resting the eyes. Some companies, such as Apple, have also incorporated reminders into their software to encourage proper viewing devices such as iPads and iPhones.
Conclusions
Digital devices aren’t going anywhere and a significant portion of our patients are feeling the effects of using them for extended durations. As eyecare providers, it’s up to us to remind them of the Golden Rules of Visual Hygiene.
Giving patients the resources necessary to combat and prevent DES and have clear, comfortable vision during their time on screens is paramount to quality patient care.
Yes, all of the considerations and discussions above may take chair time and require troubleshooting and lifestyle changes. However, satisfied, happy patients tend to be quite appreciative, loyal, and great sources of future referrals.
