As we shelter in place to slow the spread of COVID-19, working from home has become a regular routine. For many of us, this means our daily screen time has become exacerbated, and people are wondering how it’s impacting our long-term eye health.
First, I want to stress that this is not just a COVID-19 issue. Anything we’re doing in the next month or two is probably not going to cause any direct problems unless it becomes a habit. Digital eye strain or computer vision syndrome (CVS) has been around for a long time, but it’s likely being intensified and becoming more common in these current conditions. There’s so much about blue light (the type of light emitted by screens) that we don’t know. However, there are a few ways our bodies are affected by blue light that we do know about.
What Happens If Your Stare at a Screen Too Long?
First thing affected is our focusing ability. When we look up at something that is closer than 3 feet away, our eyes turn on our focusing system. When we’re young, we have this great ability to keep turning it on and off very easily. Circumstances vary, but around age 45, our flexibility is not there. That’s when people need reading glasses, bifocals, or multifocal/bifocal contact lenses to read because they can’t flex that muscle or that focusing system as well. As we mature even more, that focusing ability just isn’t there, and prescription glasses or contact lenses are necessary for that working distance.
The second thing affected is the muscles in our eyes. We use these muscles to keep things aligned, meaning the eyes are physically moving in and out. That muscle convergence can cause double vision or strain on the eye.
The third thing is ocular surface issues, and this is probably one of the biggest things when it comes to digital screens. It helped bring the whole CVS issue to light. When we are watching or working on a screen, we stare; we get very intoxicated by the screen; we don’t want to look away. We get so focused, we forget to relax and blink our eyes.
We blink almost 10,000 times a day, but when you work on a computer screen, that’s reduced by about 50%. When you don’t blink, the tears on the front surface of your eyes begin to evaporate. This happens because the layer of your eye’s surface that prevents tear evaporation can’t work overtime like it would need to. That’s when we experience dryness, burning, redness, and the sensation of a foreign body in the eyes. These are all part of the triad of dry eye from lack of blinking called evaporative dry eye, which is very common among computer users.
How Long Is “Too Long” and How Can You Rest Your Eyes?
Too long is when you get symptomatic, but that varies for people based on what their normal ocular posture is and what they do. Too long for someone who isn’t wearing the right corrective lenses could be 5 minutes, but too long for somebody who is following all the rules and doing everything right might be longer.
“Too long” varies at different ages, as well. For anyone over 21, it’s part of your life. For kids, it’s a little bit different. The American Pediatric Association (APA) recommends that you keep screen time for kids less than 4 years old to no more than 1 hour a day. Unfortunately, that’s likely not going to happen. For everyone, I recommend taking a break at least every 2 hours. I don’t mean just the 20-20-20 rule, which is every 20 minutes, look at something 20 feet away for 20 seconds. I mean a total break every 2 hours.
Common Complaints…and Misconceptions
When I do my exams, I’m trying to get the patient’s best correction for glasses or contacts, so I include questions like, “Where’s your working space? Are you on a laptop or a desktop? How far away is the screen? Have you ever had any issues?” Most of the time, I get the answer, “No, I’m fine.”
In this case, I’ll dig a little deeper and ask if their eyes ever feel tired at the end of the day or if they ever get red. That prompts the usual answer, “Yeah, but that’s normal.” It’s interesting that patients just assume that to be normal. I explain, “Yeah, it’s normal because it’s a consequence of working on computers, but you shouldn’t accept that as ‘normal.’”
I explain that they can and should do something about it. For example, you wouldn’t expect to go to work right now without any personal protective gear on, right? So why would you just accept a non-optimal desk setup or work environment? Yes, we all get tired at the end of the day, but you shouldn’t come home physically ill because of what you have to do at work.
How Can You Mitigate the Effects of Screen Time?
We know the cause of the issues: working on a computer and the environment. Now, we need to do something about it. Here are some solutions you can implement right now.
The first thing to rule out is uncorrected refractive error or the need for glasses or contact lenses. If someone already wears corrective eyewear, we make sure the prescription is up to date. A lot of people think they can see fine, but maybe they see better out of one eye, causing one eye to overcompensate which can cause discomfort. The aim is to get both eyes to see clearly at the same distance. Reading glasses might benefit somebody who isn’t ready for bifocals or is wearing contact lenses but needs additional help when they’re working on a computer.
Young people who spend a lot of time on their computers or even reading books without giving their eyes a break, their eyes get locked into this focus up close and can’t relax. Things in the distance become blurry, almost like a pseudo myopia, or false nearsightedness. When I was at the University of Chicago, I’d see this a lot in law students. By the end of their first semester, they’d come to me and say, “I’ve never needed glasses in my life, and now I can’t see at night when I’m driving or walking home for school.” I would give them very low prescription reading glasses so the lenses would do some of the work and their eyes wouldn’t be as strained.
Having the appropriate glasses or contacts that are set to the appropriate distance is important, and that might require multiple pairs. We’re just trying to eliminate all the circumstances that cause problems.
Another issue is lubrication. As I mentioned, your blink reflex is reduced while looking at screens, tears evaporate, and all these symptoms like dryness and burning occur. For those who have a computer, work on a computer, etc., I suggest they keep a bottle of lubricating drops right by their device to use every couple of hours prior to getting symptomatic. Your vision will get blurry if your tears are evaporating, so that might be another reason why someone would experience blurry vision after long hours on screens.
This may sound silly, but I’ve recommended blink exercises, too. When I was in school, we had this exercise we did while watching TV: continually blink your eyes very consciously during the commercials. When the TV shows starts again, you can go back to “normal.” Anytime you do something like that, it’s developing a habit, which could be beneficial while working on screens. If you’re surfing the web, find some time to do a similar blink exercise.
Control the environment around you. This can mean a lot of different things. One of the most important things to look for is glare on your screen. If there is light going directly onto the screen or shining from behind the screen, it can cause your eyes to work harder. Glare can be reduced by changing the lighting around the computer. When I work from at home, I have to change where I sit throughout the day because of lighting.
Head and body positioning are extremely important, as well. Everybody thinks your computer should be directly in front of your face and your eyes should be even to the middle of the computer screen. That is the worst position you could ever be in. Your head and neck should be aligned, and your eyes should be looking down slightly about 4 or 5 inches. Basically, you should be sitting higher than your screen and looking down. That does 2 things: if you are wearing progressive glasses or bifocals, it gets your eyes aligned to the near portion of the focal point of those glasses. Next, it reduces the amount of ocular surface exposure, meaning your eyelids are covering a bigger part of your eyeball reducing the surface area exposed to evaporation.
Blue Light Glasses
People ask me all the time, “Should I get blue blocker sunglasses or blue light glasses?” In my opinion, it’s not going to hurt. I don’t see the problem, but we just don’t know for sure how beneficial it really is. However, I think antireflective coatings should be on the front and the back surface of the lens to help pull light away and reduce glare.
If we could prevent blue light from entering the eyeball, that could help relieve many of these issues. Our lenses naturally get more yellow as we age because it has absorbed more UV light from the sun, and it’s believed that adults have less blue light that reaches our macular retinal surface. On the contrary, kids don’t have that natural yellowing yet, so it’s important to engage in extra filtering like blue light glasses, screen protectors, etc. Absorption and deflection of blue light is important, regardless of the method in which it’s done.
Nutritional supplementation is very beneficial. We’ve seen lots of studies that show the overall macular pigment on the retina, which is what protects our retina from damage that can lead to severe vision loss, can be enhanced using zeaxanthin and lutein (Z+L) supplementation. The more, or denser, macular pigment we have, the safer our eyes are from blue light and other damages.
Quite honestly, almost everybody could benefit from supplementation, but we typically think of it as a solution for the older crowd because of the AREDS 2 clinical trial. The AREDS 2 trial tested the impact of nutritional supplementation on age-related macular degeneration (AMD), an eye health issue most common in people aged 65 and up. Our elderly patients sometimes complain that when they go outside and get a blast of sunlight, they feel blinded for a few minutes (photostress recovery). Research has shown that Z+L supplementation can help reduce that temporary blindness and speed recovery.
There’s also a lot of research supporting Z+L supplementation as a method for reducing some of the symptoms that we see with CVS such as contrast sensitivity, eye fatigue, and photostress recovery. When I’m in an exam room, I tell my patients that they have a choice: either cut back on screen time or consider wearing these glasses or taking a supplement.
Now, let’s say you’ve followed all the rules, but you had to work a 15-16-hour day. That’s probably not healthy because that means you’re depriving yourself of other things. The more you’re on your laptop or your iPad, the less time you’re spending physically moving around or going outside which leads to a deficiency in Vitamin D. Supplementation can also help fulfill this need and support our eye and overall health.
It’s important we have these conversations. While we’re not 100% certain of the impact yet, I think we need to share the awareness of these issues and the options we have.