Computer vision syndrome: Does looking at a screen cause dry eye?

Many people spend the majority of their waking hours looking at a computer, smartphone or tablet.

One of our standard introductory questions when we meet a new patient at SkyVision is, “What kind of work do you do?” I like to joke that a more telling and actionable question might be, “How do you use a computer in your daily work life?” Think about that for a minute. No matter what it is that people do for a living, what kind of job they may have, the nuts and bolts of their daily activity is essentially looking at a screen. Almost all of these people present with symptoms that we associate with dry eye.

This begs the question: Does using a computer of any kind cause dry eye syndrome (DES), and if so, how?

I think this is not only an important issue for today, but if you look around at people going about their daily business, you can’t help but notice the ubiquity of the computer screen. If you include smartphone use, the number of hours spent viewing a personal screen might constitute a substantial majority of waking hours. DES has traditionally been described and studied as a disorder of older individuals. Our emerging understanding of DES as a progressive inflammatory disease that can be diagnosed in mid-life certainly expands both the impact of the disease as well as the need for the DES specialist to engage and treat younger patients. It is highly likely that smartphone use among the relatively young, even teenagers, may expand this impact even further.

Screens causing problems?

So, what do you think? Is it the computer screens themselves that are causing DES symptoms and presumably, if we look at and test these patients, also producing DES signs? Your patients are complaining of burning, tearing, blurring and fluctuating vision after using their desktop, laptop, tablet or phone. Let’s consider what we know about how looking at a computer screen, or visual display terminal (VDT), affects the eye.

Near tasks of all kinds produce an almost universal response in humans, including a significant decrease in blink rate. The normal adult human blink rate is approximately 12 per minute. Doing any task that involves near vision reduces this rate to half or less. Over time, this decreased blink rate results in excess evaporation of tear fluid, even in the absence of tear abnormalities such as meibomian gland dysfunction or Sjögren’s. The longer you perform near tasks, the greater the likelihood that this excess evaporation will cause symptoms to arise.

There is some hard science emerging that may explain why this “near reflex” causes dry eye symptoms even in individuals who have not otherwise been diagnosed with DES. Uchino and colleagues published an interesting study in the August issue of JAMA Ophthalmology (formerly Archives of Ophthalmology for us old folks). The Osaka Study showed a time-dependent decrease in measured tear volume of mucin in office workers who worked on VDTs. Participants who worked longer hours on a computer had a lower level of tear mucin than those who worked fewer hours. The particular mucin studied, tear mucin 5AC, is thought to increase the wettability of the surface epithelium of the eye because of its inherent hydrophilic nature. This may well answer the question of how using a computer causes dry eye symptoms.

Back in my day

But that still leaves us with the burning question: Is there something about the computer screen, the personal VDT itself, that is actually causing dry eye? I am going with “no,” and I am playing my “old guy” card to make this call. Anyone older than 45 years who has been taking care of regular patients, doing what might be called general ophthalmology, has been hearing these same complaints and taking care of the same problems since a time well before the advent of the smartphone or the universal use of computers in every job in North America. You see, in the days of Steve Jobs v1.0, before iPhones and iPads, Wikipedia or Facebook, we had these things called “books” (you younger folks can Google it). People used to read these books, as well as their cousins magazines and newspapers. Folks had hobbies such as stamp or coin collecting, needlepoint and sewing. Heck, there were people who would assemble their own computers (presumably in their garage) by hand. Crazy, I know.

Here is the rub: Reading a book or doing any sort of craft such as needlepoint involved prolonged periods of — wait for it — near visual tasks with an associated decrease in blink rate. Many of these folks came in complaining of tearing, burning, blurring and fluctuating vision — even after they started using electric light bulbs instead of candles. They called it “eye strain,” just like computer users do now. The difference in 2015 compared with 1995 is twofold. People are using their screens for hours on end, sometimes 8 or 9 or 10 hours straight, and unlike patients in an earlier time, the advent of cell phone use by teens and seniors alike is bringing in younger and younger patients with these complaints.

It is a good thing that we have so much at our disposal to treat “eye strain” caused by DES associated with computers. I was much more successful at convincing my older patients to put down Valley of the Dolls in paperback than I have been in getting them to take a break when they are binge-watching Vengeance on Hulu.

For more information:

Darrell E. White, MD, can be reached at SkyVision Centers, 2237 Crocker Road, Suite 100, Westlake, OH 44145; 440-892-3931; email: dwhite@healio.com.

Disclosure: White is a consultant for Bausch + Lomb, Allergan, Nicox, Shire and Eyemaginations. He is on the speakers board for Bausch + Lomb and Allergan.