By this point, most of us have heard that computers, smartphones, tablets, and other digital devices have some kind of impact on our eyes. Blue light lenses are incredibly popular, and everyone is looking for ways to prevent computer vision syndrome or digital eye strain.
We’re still learning about the precise causes and effects of digital eye strain. But we do have some insight into how this condition impacts your overall health.
Every part of your body is designed to work a certain way. Your eyes were intended to spend the day looking at different objects at different distances in different kinds of light. Unfortunately, that is not really how we use our eyes. Whether we’re going to school, you’re working, or even just lounging around at home, most of us spend a good portion of the day looking at some kind of screen.
Looking at an object directly in front of you for hours is exhausting to your eyes. To put it into perspective, think about holding a ping pong ball straight out in front of you with your arm extended. A ping pong ball isn’t heavy or difficult to hold. For the first few minutes, you wouldn’t really notice anything. By an hour, you would definitely be uncomfortable. And after a few hours, you most likely wouldn’t be able to hold your arm in that position anymore.
This is the same principle that causes your eyes to feel tired after a day of looking at computers, mobile devices, tablets, and other digital components.
Of course, school work and office work is hardly a new concept. For hundreds of years now people have spent 8 hours or a day or more reading and writing. So why is eye strain such a new thing? Why does it seem to be specific to digital devices?
The major reason has to do with how we use digital devices. Most people hold a book or newspaper approximately 40 cm from their face when they’re reading. That position is relatively comfortable for your eyes. Meanwhile, most people hold their smartphones and tablets about 32 cm from their face. This position is far less comfortable and forces your eyes to work much harder to focus on what you’re trying to see.
Another significant component of digital eye strain is blink rates. On average, we blink between 19 and 26 times per minute. When we’re using a computer or digital device, the average blink rate goes down by 60%. Blinking is what keeps your eyes hydrated. If we stop blinking properly or frequently enough, our eyes become dry, tired, and uncomfortable.
Your eye focuses on different objects at different distances through the lens, which is controlled by muscles. Just like any other muscle, overuse leads to soreness and fatigue. Forcing a muscle to hold a position for a long time will cause discomfort and exhaustion.
The process of blinking is designed entirely to keep the eyes clean and hydrated. Each blink introduces more tears, replenishing them as they evaporate. When you’re working on a phone, tablet, laptop, or other similar devices, your blink rate slows down, allowing tears to evaporate from your eyes without replenishing them. As your eyes dry out, they become irritated.
Regular headaches can be a symptom of many things, from dehydration to depression. But very frequently, headaches are a symptom of vision issues. When your eyes have to work particularly hard due to a refractive error or digital eye strain, it often results in a headache.
As our eyes grow tired, we may start to unconsciously compensate by craning our neck forward or hunching over our desk to see better. As a result, people suffering from digital eye strain often experience pain in their shoulder and neck muscles. With the proper office ergonomics, this can be avoided, and the overall impact of digital eye strain can be greatly reduced.
Some optometrists and medical professionals consider sleeplessness a symptom of digital eye strain. This stems from the belief that blue light, which is emitted by digital displays, is one of the leading causes of digital eye strain.
Blue light is a specific range of ultraviolet light which can alter your circadian rhythm, or your sleep schedule. Staring at a digital screen for too long, or too close to bedtime can prevent your brain from releasing melatonin, the hormone that makes you drowsy.
So much of digital eye strain comes from too much near work. I recommend the 20-20-20 rule to give your eyes a chance to rest throughout the workday.
Every 20 minutes, stop looking at your phone, computer, or device. Choose a spot about 20 feet away, and stare at it for at least 20 seconds. The 20-foot focus point is considered to be the most neutral position for your eyes. This is sort of like stretching your legs after sitting the same way for 20 minutes. It can make the rest of your workday much more comfortable.
If you have trouble remembering, set reminders on your phone or computer every 20 minutes throughout the day.
Setting up your office or workspace ergonomically can help alleviate some of the strain on your eyes and your body.
Your computer screen should be about an arm’s length away from your face. The top of your screen should be about 20 degrees below your eye level and tilted up towards your face. Position your monitor to eliminate as much glare as possible.
This is a tricky question, to which the answer is both yes and no. Blue light filtering glasses or lenses can block up to 99% of blue light from entering your eye. However, there is now some debate as to whether blue light actually triggers digital eye strain or not. Studies have been released on both sides, dismissing and supporting the use of filters to alleviate symptoms.
Regardless of the impact blue light may or may not have on digital eye strain, protecting your eyes from blue light is still important. Studies indicate that blue light exposure may increase your risk of cataracts, macular degeneration, and other eye diseases. Scientists believe blue light exposure is cumulative, meaning the sooner you start filtering blue light, the better.
Doctors have been studying the impact of digital displays on the eye since computers became a regular part of office life. However, all of the technology that we use, particularly its modern iterations, are quite new. At this point, it’s still too early to really tell what sort of long-term effects digital eye strain could have on your health.
Until we know more, it’s best to protect your eye health by taking frequent breaks, maintaining an ergonomic workspace, and visiting your optometrist regularly.
DR. KEVIN HESTERMAN
Dr. Hesterman was born in Regina, Saskatchewan. He graduated from optometry at Waterloo in 2000. He and his wife, Rhonda, have three children. He enjoys swimming, biking, and running, having completed several triathlons. Hiking, skiing, and playing the piano and guitar are other interests. He has volunteered with Big Brothers and Big Sisters and was on the executive committee for Optometry Giving Sight, a charity raising money for third world optometry. Dr. Hesterman is currently on the executive council for the Alberta Association of Optometrists.