All That Screen Time Matters When It Comes to Eye Health

Anyone who’s lost track of three hours while staring at their computer might be familiar with the feeling of peeling off eyes that’ve been plastered to a screen.

As it turns out, staring at our phones, tablets and laptops for too many hours a day is not good for our eyes. It can cause symptoms of digital eye strain, which stems from the hard work our eyes have to put in while navigating a screen.

According to the American Optometric Association, using phones, computers and other devices requires specific, but particularly demanding, “skills” of our eyes, including ocular mobility, coordinating moving from one position to the next; accommodation, the ability to switch focus from one distance to the next; and vergence, aiming the eyes toward the nose and away from the nose, depending on distance.

“Our eyes were not designed to use computers and digital devices, especially for long periods of time,” Dr. Robert C. Layman, a past president of the AOA, said in an email.

“As a result, many people who spend long hours reading or working on screens experience eye discomfort and vision problems.” 

In the world we live in and with everything awesome that’s available at our fingertips, it’s probably not realistic to cut out screen time completely (though it can be done). So here’s what to know about what being plastered to a screen can do to your eyes, and how to safely peel them away.

Eye strain and blue light: What too much ‘screening’ does to your eyes

There’s been a lot of debate about blue light, which we get in large doses from the sun, and in smaller amounts from our screens. Exposure to blue light signals to our bodies that it’s time to feel awake, which is one reason using your phone before bed can be one of the biggest sleep disruptors, because it messes with our sleep-wake cycle. 

While research does show that exposure to blue light over time from the sun can increase the risk of diseases that cause vision loss, including macular degeneration and cataracts, the risk hasn’t yet been shown to carry over to the light that comes from our electronic devices, according to the American Macular Degeneration Foundation. Research available tends to show damage to retinal cells at 3 microwatts or more, the AMDF says, compared to the typical 1 microwatt of light that comes through our screens. 

Dr. Matt Starr, clinical spokesperson for the American Academy of Ophthalmology, said in an email that blue light, by itself, “does not cause permanent damage to the eyes.” 

Layman, however, said that overexposure to blue light can cause digital eye strain, which in some patients can lead to age-related vision problems. 

Effects of blue light aside, eye strain is a common and uncomfortable problem. While it may be experienced “a little bit differently from person to person,” it’s a group of symptoms that come from staring at a screen for a long time, according to Starr. 

“Common symptoms include blurry vision, foreign body sensation, itchiness, headaches and dry eye,” he said. 

Interestingly, Layman says that screen time can also lead to a higher risk of infection in some cases, because we blink less when staring at a screen. 

“Blinking helps create and spread tears across the cornea, which is what keeps your eyes hydrated,” Layman said. “When the eyes don’t have enough tears to rinse away foreign matter, they become more prone to infection.” 

So do blue light glasses really work? 

There really hasn’t been a proven medical benefit yet. But there’s no harm in seeing if they’ll help you.

“While some patients report advantages of using blue light glasses when using computers, smartphones and tablets to prevent eye strain, the fact is, there is not enough science to support or deny their benefit at this time,” Layman said. 

Personally, I sometimes use a pair of blue light glasses when I’m feeling extra eye strain or I feel myself needing extra focus, and I usually find it slightly easier to pay attention to my computer screen. But I have no idea if it’s actually helping my eyes feel less strained, or if it’s just a placebo effect that helps me shift my perspective slightly. Starr confirmed it’s maybe the latter by pointing out this study from the American Journal of Ophthalmology, which found no difference between people wearing placebo glasses and blue light glasses. 

But because blue light glasses are so cheap (I bought mine online a couple years ago for under $15) they’re worth a test run if you spend hours on end in front of a computer, just to see if it helps you at all. Prices start around $9 at places like Walmart or Amazon, or you can read our review of the best blue light glasses.

Is using ‘dark mode’ better for your eyes? 

One of the biggest cheers from the audience at the Google I/O event this year happened when the tech company announced Bard, Google’s AI chatbot, is getting a dark mode. But is this really something to celebrate, eye health-wise? 

It might depend on the brightness of the room you’re using the screen in, according to Layman. He said “dark mode” might be better in a dimly lit, but not completely dark, room and that light mode (black text on a white page, aka “positive polarity”) is better in a room with typical lighting. Layman pointed to this study from 2013, which found positive polarity allowed people to see details better. 

Starr adds that using a dark mode, or turning on “night mode” on your phone, does have some benefit in how easy our eyes are able to adjust. 

“The contrast and colors used in night mode reduce glare and is meant to help our eyes adjust more easily to surrounding light, leading to less eye strain and easier, comfortable reading,” he said. 

Similar to blue light glasses, you should try toying around with dark mode where it’s available to see if it helps your eyes at all or makes them feel less strained.

Can screen time make bad vision worse? 

When I went to the optometrist last month for an eye exam, I asked my doctor this question and he said the research isn’t there to give a causal answer one way. There may be a chicken-or-the-egg scenario at play. 

For example, people who are nearsighted may sit closer to their screens and potentially expose themselves to more eye strain or blue light, but that might not actively cause a worse prescription, but rather be based instead on the fact they can’t see well and have to scooch their face closer to the screen. 

Starr had a similar explanation: “There are some studies that suggest near work activities, such as reading or using screens for hours and hours at a time may lead to an increase in nearsightedness, particularly among children whose eyes are still growing,” he said.

According to information from the AAO on vision development, research has shown that children who spend an extra 40 minutes outdoors each day have a lower risk of getting myopia or severe myopia (a very strong prescription), compared to kids who spent more time indoors, either using computer devices or reading. The AAO adds that there’s no direct link, but that having children spend more time outdoors (and less time inside staring at a screen) is good for their health.

Read more: Is Your Vision Getting Worse? It’s Time for an Eye Exam

Tips for protecting your eyes from tech

Whether or not staring at a screen all day damages your eyesight permanently, there are some easy steps you can take to make them feel more comfortable. 

• Keep your phone “book-reading distance” from your face. This tip comes from Layman, who says it’ll lessen the focusing demand on your eyes.
• Make your font bigger. Another tip from Layman, upgrading your font size may also make for a more comfortable viewing experience. 
• Follow the 20/20/20 rule. Starr and Layman recommend that every 20 minutes, you take a 20-second break from your screen by looking 20 feet away. “Blink, close the eyes, and look 20 feet away during the break,” Starr said.
• When possible, use a pen and paper. (Even if you feel ridiculous.) This tip is not backed by science, but it’s helpful to me (I’m very nearsighted and work in front of a computer all day). I use a physical notebook for a calendar because it’s one small relief for my eyes, which are normally glued to my laptop. I also use pen and paper if I’m writing anything for fun, and to take notes. 
• Limit screens one or two hours before bed (and whenever else you can). This bedtime rule is a tip from Starr. Not only will limiting screen time before bed help your eyes, it may also help you feel less stress and detach from the duties of the day. Learn more about how to cut back on phone time.

Both Layman and Starr stressed the importance of eye exams, typically recommended at least every two years, but more often if you wear glasses or contacts, or if you’re experiencing discomfort or pain in the eye region. Your optometrist or ophthalmologist will be able to prescribe medicated drops or find other causes for eye discomfort beside screen time, in case you need it.

Read more: Take Instagram Off of Your Phone and Thank Me Later