Screen time may be taking a toll on your vision

Published on Saturday, February 1, 2025

By: Gary Pettus, gpettus@umc.edu

If you’re struggling to focus on these words as you read them on your computer screen, if they appear to be swimming underwater, you may have come to the right place.

Digital eyestrain is a common, and preventable, condition, but getting most people to significantly reduce their time on computers, smartphones, virtual reality (VR) headsets and other digital devices probably isn’t within sight.

Still, there are ways to relieve eyestrain symptoms, including measures that can be taken during actual screen time – good news for the large eye-stressed population.

“It’s upwards of 60 million people around the world, studies show,” said Dr. Bo Huang, professor of ophthalmology at the University of Mississippi Medical Center.

“Eyestrain typically develops between two to four hours of constant screen time; the biggest recommendation is to not use a screen more than four hours per day, but for many people that is not an option.”

In the U.S., the average adult devotes about seven hours a day to a screen, reports the search engine optimization website, Backlinko. Many people have jobs that depend on such digital dedication.

Whatever the reason you have to, or choose to, plant your eyes on a screen, the result can be blurry vision or dry, achy, tired eyes that can also become overly sensitive to light.

And there are potential problems that affect other body parts: headaches, neck strain and back pain from poor posture.

But there’s at least one solution that couldn’t be simpler: blinking.

“Far and away, when people have eyestrain, the No. 1 culprit is that we blink a lot less when doing visually intense tasks, regardless of whether it’s sewing, reading or watching a screen,” said. Dr. Taylor Coleman, assistant professor of ophthalmology at UMMC.

“So, be mindful about blinking and taking a break from the screen.”

Normally, the eye-blink rate is 15-18 times per minute, but it falls to less than half that rate for people working on a computer or ogling a cell phone, Huang said.

“Your eyes get dry quickly.”

In which case, experts refer you to the 20-20-20 rule: “Every 20 minutes, look at something 20 feet away for 20 seconds,” Huang said.

Need a reminder? “There are apps that will do that,” Coleman said. Google Play and Apple are among the sources.

“Another way to relieve the strain is to find a comfortable sitting position,” Huang said. “Also, adjust the brightness and contrast on your screen.”

If you happen to have a Dell computer like the one this sentence was written on, you’ll notice that there are small, lozenge-like buttons on the right side of the screen’s frame. Press the bottom one for a menu; a button above that is “Brightness/Contrast.” Press it, and the arrow buttons let you toggle back and forth between the two settings and fine-tune them.

“The screen contrast [the difference between the darkest black and brightest white] should be at around 60 to 70 percent,” Huang said. “That would provide a comfortable level for your eyes.”

You should also eliminate screen glare from lamps and window light. Another option: make your computer text bigger.

Computer eyeglasses can also be helpful, Huang said. While people may use the terms “computer eyeglasses,” and “blue light glasses” interchangeably, they are not exactly the same.

Computer eyeglasses require an eye exam and a prescription. “Some of the glasses can help with screen contrast; they are meant to reduce eyestrain,” Huang said.

Blue light glasses, on the other hand, are available over-the-counter at many stores or can be added as a premium option for prescription lenses, Coleman said. They purportedly reduce exposure to blue-violet light.

“Blue light can disrupt the circadian rhythm,” Coleman said, That is, the body’s internal clock, its natural wake-sleep cycle.

“Your retina has cells that detect blue light. When you’re holding a phone screen up to your eyes at night, the light is telling your brain that it’s daylight and it disrupts the production of natural melatonin, making it more difficult to fall asleep,” Coleman said.

“Blue light-blocking glasses are also supposed to reduce eyestrain, but there is not a lot of high-quality evidence that this is the case.”

Another line of treatment, especially for dry eyes, is artificial tears – eye drops, gels or ointments that lubricate; you don’t need a prescription for them, either.

“Ideally, if you use artificial tears more than four times a day, you want to choose a preservative-free variety,” Coleman said. “It’s gentler on the surface.”

Two conditions that can worsen dry-eye symptoms are blepharitis, an inflammation of the eyelids, and meibomian gland dysfunction – the glands along the eyelid margin either produce low quality or poor quality of oil (meibum), which causes tears to evaporate too quickly.

“Getting  those conditions diagnosed and treated should help with dry eyes,” Coleman said.

Some people turn to supplements, such as omega-3, or adopt a diet high in omega-3 fatty acids. A scientific journal report published in 2023 stated there is evidence for “the therapeutic potential” of omega-3 fatty acids for dry eye disease, but “limitations highlight the need for future research.”

In the end, and in spite of what you may have heard, there is no evidence that permanent eye damage can result from screen time, Huang said. That includes watching too much TV.

Still, it’s not easy on the eyes. “Again, the most effective way to avoid digital eyestrain is to reduce your screen time,” Huang said.

“But, since, you can’t get away from those devices in modern society, you just have to learn how to manage your usage better.”

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For an appointment with an ophthalmologist at UMMC, call 601-984-5020; to make an appointment online, go here.

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