By Cheryl G. Murphy, OD
Long before he became famous, Bob Dylan was a young musician roaming around Greenwich Village and staying with friends. One of his friends had an enormous personal library and according to his autobiography Chronicles Volume One, Dylan found himself spending hours there, enraptured by the wide variety of books on philosophy, history, poetry and politics. Of his friend’s apartment, Dylan said that “there weren’t any big bookstores around so it would have been hard to find these books in any one place.”
In today’s age of e-readers, tablets, smartphones, laptops and Wi-Fi, we all can have a friend like Dylan’s. We have been gifted with the ability to instantly obtain a plethora of news, literature, art and music online at any time and practically anywhere. We share photos, feelings and our lives. We play games, snap pictures and send messages. This new form of communication and information harvesting have slowly begun to overtake our old way of doing things. It has infiltrated our personal life as well as the workplace.
According to a 2014 survey conducted by The Vision Council, about 30 percent of adults say they spend more than nine hours a day staring at some sort of screen. The AOA says “two-thirds of Americans spend up to seven hours a day using computers or other digital devices such as tablets and smartphones.” Look around any public place at any given time of day and you will spot someone gazing down, entranced by their smartphone. The Vision Council’s 2014 digital use survey revealed 69 percent of Americans use a smartphone daily, up from 45 percent just three years prior. These new devices are considered useful and convenient but some people are experiencing a drawback to their frequent use: digital eyestrain.
“Our eyes are not built to stare at digital screens all day,” says Justin Bazan, OD, owner of Park Slope Eye and medical advisor for The Vision Council. “The modern day world we live in is one in which we are frequently in front of a computer, working from our smartphones and reading on our tablets for hours on end. For many of us, this leads to
￼tired, sore and fatigued eyes, and even headaches. Some of us may experience problems focusing. These are symptoms of digital eyestrain.”
The Vision Council’s 2015 Digital Eye Strain Report, “Hindsight is 20/20/20,” (see graphic on page 102) defines digital eyestrain as “the physical discomfort felt by many individuals after two or more hours in front of a digital screen.” The report states that the symptoms commonly associated with overexposure to digital devices include eyestrain (32.8 percent), neck/shoulder/back pain (32.6 percent), headache (24 percent), blurred vision (23.3 percent) and dry eyes (22.8 percent). The Vision Council also emphasizes that there is not a single cause for digital eyestrain but that many factors contribute to it including “posture, personal device use habits and the blue light emitted from screens, lighting and even sunlight.”
Dr. Bazan asks his patients to describe their office setup and work habits in order to assess whether or not they may be putting their eyes and bodies at risk for digital eyestrain. In his experience, he has found that the workplace is often the most common and biggest culprit, and he may be right. In 2012, Joan Portello, OD, and colleagues from SUNY College of Optometry in New York surveyed 520 New York City office workers and found that “approximately 40 percent of them had a ‘tired eye feeling’ (at work) at least half of the time (they were there).” The good news is that there are many steps a person can take to help minimize their risk for digital eyestrain at work and at play.
Keep your distance. Your desktop computer screen should be 20 to 24 inches or an arm’s length away from your eyes. Extend your arm toward it and you should be able to “high-five” the screen. Your smartphone or tablet should be held at about 16 to 20 inches away from your eyes.
“I find that many patients have working distances that are way too close,” says Dr. Bazan. “This puts extra stress on their binocular and focusing systems, leading to digital eyestrain.” A study conducted by Mark Rosenfield, OD, and colleagues at SUNY Optometry in 2011 showed that people tend to hold electronic devices 2 to 9 inches closer than they would typically hold other printed material. This closer-than-needed distance could put more accommodative and convergence demands on the eyes unnecessarily. Dr. Bazan tells his patients that they need to become cognizant of the distance at which they are holding their devices and consciously correct themselves if that distance is too close. He also adds that they need to check the distance they are away from their laptop and desktop computer screens: “They simply need to back up their computer screens to an arm’s length away and hold their handheld devices no closer than the Harmon distance.” The Harmon distance is “an elbow’s distance away,” meaning the distance your elbow would be away from your eyes if you put your closed fist next to your eye. If possible, near work should be held no closer than this distance.
People need to let their eye doctors know if they are experiencing blurriness, double vision, headaches or a tired feeling when working on the computer, looking at a tablet, smartphone or book, or when doing any other type of near work. Optometrists can
￼assess a patient’s binocularity and accommodative functioning during a thorough, comprehensive eye exam and test for any underlying issues that may get aggravated when doing excessive near work or near work that is not ergonomically correct.
Adjust your viewing angle. You should be looking slightly down toward your computer screen or device, never up. Also, your computer screen should be perpendicular to the windows in your office to help minimize glare.
Another common issue that Dr. Bazan finds is that sometimes his patients have their computer monitors up too high. “Instead of naturally converging on a near object, upgaze forces us to fight divergence, inducing eyestrain,” Dr. Bazan says. The AOA recommends that screens be viewed at an angle of about 15 to 20 degrees below eye level which means that if your eyes were looking straight ahead, the center of your computer screen would be about 4 to 5 inches lower than your line of sight. Dr. Bazan adds that if one does not have the correct viewing posture and is looking up while viewing a screen, that it “opens our eyes up wider (which can) potentially lead to dry eye,” another possible symptom of digital eyestrain.
Additionally, computer screens should be set perpendicular to windows or in an orientation where natural light coming through the windows does not produce glare or detract from the contrast of the screen. Blinds or drapes on windows can also help to minimize incoming glare. If a person is wearing glasses, an anti-reflective treatment on the front and backsides of the lenses can reduce glare and ease visual discomfort.
Take breaks. Use the 20/20/20 rule. Every 20 minutes, take a 20-second break and look at something 20 feet away or beyond to relax your eyes and allow them to return to a more natural blink rate.
“The 20/20/20 rule has proven helpful for those who are able to make it a habit,” says Dr. Bazan. “Every 20 minutes, take a 20-second break and look at something 20 feet away.” This will give your eyes a chance to relax from focusing and aiming at something up close for so long, and it will improve your blink rate which can help prevent dryness.
Studies have shown that when we use a computer, smartphone, read or watch TV, we blink less frequently than we do during other activities throughout the day. When we do not blink, the layers of tears that naturally coat our eyes at all times have a chance to evaporate away. The upper lids usually replenish the surface of our eyes with new layers of tears upon each blink. However, when we don’t blink, the ocular surface gets dry and does not get replenished like it should. It has been long understood that our eyes can get dry when our blink rate is reduced but a 2013 study by Dr. Portello and colleagues at SUNY Optometry revealed that it may not only be the decreased blink rate that exacerbates dryness during computer use but also the fact that some people may not be blinking as fully as they should during certain near tasks. Incomplete closure
￼of the eyelids during the blink can also accelerate dryness because the area of the cornea where the lids do not come together is repeatedly left exposed and its tear layer not properly replenished.
Decrease overexposure to blue light. Setting screen brightness to half of the available intensity or less can help to reduce the level of potentially troublesome blue light emitted by computer screens and digital devices. Wearing lenses that filter out some blue light is even more effective.
The screens and lights of today seem whiter and brighter because they emit a higher concentration of blue light than their predecessors. Older computer screens, televisions and even lightbulbs used to emit a high concentration of yellow light. While blue light does seem to make things look nicer, there are some disadvantages to it, especially if we are overexposed to it at the wrong time of day.
Blue light from natural sources like the bright blue sky and from artificial sources like your smartphone can affect a person’s sleeping pattern. There are specialized cells in the retina that sense blue light, and when they do, they signal the body to remain awake and alert. The absence of blue light tells your body it is likely nighttime and time to get some rest and go to sleep. If you are stimulated by an artificial blue light source at the wrong time of day, your body will temporarily suppress its melatonin production, a hormone that makes the body sleepy and helps to set your circadian rhythm. Experts say you shouldn’t be stimulated by artificial blue light sources like tablets, smartphones and computer screens within an hour of your desired bedtime, otherwise you might be shifting your body’s sleep cycle to a later than desired time, and that can have negative effects on your health.
Even during the daytime, people should consider limiting their exposure to blue light. Studies have shown that like ultraviolet light, overexposure to blue-violet light specifically may lead to cumulative damage of retinal cells. “We now believe that there is a link to the HEV light (emitted)from our digital screens and damage to the macula,” says Dr. Bazan. “I let patients know that a great way to reduce this risk is to make sure their computer eyewear has an HEV light filter.”
The Vision Council says that a staggering “72.5 percent of adults are unaware of the potential dangers of blue light to eyes.” Gearing up against blue light by wearing glasses that selectively filter out some blue-violet light is another way to decrease our exposure to blue light and its potentially hazardous effects besides merely lowering the brightness of our screens and keeping a good working distance away from them.
Gear up. Consider a pair of glasses suited for computer or close work (with a prescription if needed) that has an anti-reflective treatment and that is designed to selectively filter out blue-violet light.
“A pair of computer eyewear, with the ideal prescription, lens design, tints and non-glare lenses, can also be extremely helpful in minimizing digital eyestrain,” says Dr. Bazan.
An eyecare provider can determine the visual needs of a patient and then provide recommendations as to what will best combat digital eyestrain in that person’s personal life and work environment. This may involve a special pair of glasses to be used while at the computer with a particular prescription or lens design or lens treatment options added to their primary pair of glasses to help ease eyestrain while using the computer or digital devices for prolonged periods of time. Anti-reflective treatments on the front and backsides of lenses would be helpful in minimizing glare, and lenses that selectively filter out blue-violet light would benefit those who spend many hours a day on the computer or digital devices including those who tend to use them in the evening or who are at risk for macular degeneration.
It is important that we have the proper prescription while we are at the computer. Sometimes people will simply increase the font size if they can’t see print of a certain size on their screens. While increasing the font size may help to prevent squinting, which studies have shown can further decrease one’s blink rate and contribute to dryness and eyestrain, it doesn’t solve the root of the problem. Corrective lenses that allow for effortless clarity without squinting can better eliminate focusing difficulties without having to adjust font sizes or magnify the print on the screen, which can decrease the screen’s field of view and make visual tracking a bit more difficult.
Adopting digital devices into our daily lives has given us many perks by creating faster lines of communication and information sharing, and it seems that the digital realm is here to stay. However, now that we have adopted digital devices into our culture, we have to adapt to them and protect ourselves from any negative effects they may result from their use. Luckily, eyecare and eyewear providers have the innovations, tools and knowledge needed to help ensure that digital devices won’t leave us “tangled up in blue” or become a pain in the neck. ■
Cheryl G. Murphy, OD, has been widely published and received the 2013 New York State Optometric Association Communications Award. - See more at: http://www.2020mag.com/l-and-t/53191/#sthash.40hHo0IO.dpuf