As COVID-19 continues to affect nearly every aspect of our lives, work and school have become common place in our homes. With the added technology, our daily screen time has increased, and many people wonder how it’s impacting our long-term eye health. For parents, the concern grows, as some are concerned with the impact screen time can have on their children’s development—physically, mentally, and socially.
First, I want to stress that this is not just a COVID-19 concern. Our screen time use over the next month or two probably won’t cause any direct problems unless it becomes a habit. What we are seeing is digital eye strain or computer vision syndrome (CVS), which has been around for a long time, is being exacerbated, and related symptoms are becoming more common in these current conditions.
The most common physical symptoms are tired, dry, strained eyes and even headaches due to too much screen time. The dryness is caused when blink rate decreases by nearly 50%. This causes the tears on the front surface of the eyes to evaporate because the layer of your eye’s surface that prevents tear evaporation can’t keep up with demand.
The strain and fatigue come from our eye muscles constantly working. When I see kids in the practice sitting in the waiting room, they tend to hold their devices up against their nose. If you give them a book to read, they keep it at the same working distance the whole time, but on a screen (phone, tablet, etc.), they keep bringing it closer and closer to their face. The closer something is, the harder our eye muscles work to focus.
Furthermore, the more time spent on screens means the deprivation of other activities like going outside. Vitamin D, also known as the sunshine vitamin, is essential for kids to support healthy development of the eyes. It’s also been demonstrated in third or fourth graders that a couple hours of sunshine every day is essential to decrease the onset of myopia or nearsightedness.
Another thing affected by screens is our melatonin levels, and that messes with sleep. As an adult, I figured out I can turn devices off sooner to help with my sleep, so I try to put things like my phone away before going to bed. Kids need about 9 to 12 hours of sleep, but they’re not getting it because all the screen time has impacted their melatonin levels. Additionally, their cortisol levels are elevated, and they get more agitated or more violent.
Unfortunately, I don’t think anybody knows how long “too long” is because it varies based on a person’s current eye health and what they do. Generally, we tell patients that too long is when you become symptomatic. For someone who isn’t wearing the right correction, too long could be 5 minutes. For somebody who is following all the best practices for screen time, too long might be a lot longer.
“Too long” also varies by age. For anyone over 21, it’s part of your life, and we have to figure out how to give you the best-case scenario to try and mitigate symptoms. For kids, it’s a little bit different. The American Pediatric Association (APA) recommends that you keep screen time for to no more than an hour a day for kids 4 years old and younger. As age increases, so does recommended screen time, but not to the degree of which kids are realistically on them. My son is 17, and I have to practically drag his phone or his iPad away from him!
If we can keep blue light from entering the eye, that could be very helpful. Our lenses naturally get more yellow as we age because of more UV light absorption from the sun. It’s believed that adults have less blue light that reaches our macular retinal surface because of this natural yellowing. On the contrary, kids don’t have that natural yellowing yet, so it’s important to engage other protective measures.
Parents ask, “My kid’s on the computer all the time. Is there anything we could do?” Kids don’t usually want to hear it from their parents; they want to hear it from a doctor. Even though I’m a doctor, my son doesn’t want to hear it from me. I have to show him an article or something. When I’m in an exam room, I tell my patients or their kids that they have a choice: either cut back on screen time or consider adding other protective options. Here are some of my common suggestions.
For anyone, 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.
People ask me all the time, “Should I get blue blocker sunglasses or blue light glasses?” There is some science that supports these types of frames being beneficial, and any kind of barrier between blue light and the eyes is going to be a good thing. Additionally, I think antireflective coatings on the front and the back surface of the lens are important to help pull light away and reduce glare.
Studies show that macular pigment, the protective layer in the retina that absorbs blue light and reduces damage that can lead to severe vision loss, can be enhanced using nutritional supplementation, specifically zeaxanthin and lutein (Z+L) as found in EyePromise Screen Shield Teen. The more, or denser, macular pigment we have, the safer our eyes are from blue light and other damages. Now that we know that blue light is emitted by our digital screens, we should build up their macular pigment and keep it built up.
Research shows that Z+L supplementation can also help reduce some of the symptoms that we see with screen use such as decreased contrast sensitivity and eye strain and fatigue. It also helps reduce photostress recovery, which is when you step into bright sunlight and feel blinded for a few minutes. Supplementation can help reduce that temporary blindness and speed recovery.
Absorption, deflection, and reduction of blue light is important, regardless of the method in which it’s done. It’s important to start that conversation. Years ago, there wasn’t much we could do for kids whose vision kept getting worse other than giving them stronger and stronger prescription lenses. Nowadays, we have options. We’re not 100% certain of the impact yet, but I think people should know what those options are.