Can staring at a screen make me go blind?

Americans spend an average of 6.3 hours a day accessing the internet on their devices. That’s a lot of online shopping.

These long hours usually lead to one thing: burning, itchy, tired eyes — and fear that all this eye soreness will eventually turn us blind.

According to Dr. Arvind Saini, an ophthalmologist affiliated with Sharp Community Medical Group, extensive screen use has its downsides, but blindness isn’t one of them. “There is no clinical evidence that prolonged screen use causes permanent vision loss,” he says. “Dry eyes and eye strain, yes. But nothing long term.”

We asked Dr. Saini to share some important information about TV and digital device screens, and the impact they have on our eyes.

Why can screen use cause red, burning eyes?
The soreness you may feel after viewing a screen is a condition called digital eye strain. Symptoms include dry and irritated eyes, blurry vision, watery eyes, and headache.

Digital eye strain has less to do with the total time you are viewing a screen and more to do with the uninterrupted duration of your viewing — the amount of time you spend staring at a screen without blinking.

In general, we blink 15 times a minute. However, our blink rate lowers to less than 7 times a minute when looking at a screen. Less blinking leads to drier eyes, which bring on the symptoms of dry eye, such as redness and burning.

Can digital eye strain cause long-term damage?
There is no evidence that screens cause irreversible harm to the eye. Eye strain can result from anything that requires attention, such as needlepoint, reading a book, etc. You wouldn't assume that doing needlepoint would damage your eyes, but because more people are on their screens these days, fears about digital eye strain have risen.

Are some devices worse than others in causing digital eye strain?
There is no difference between any of these screens from a radiation or damage perspective.

Do you have a recommendation on preventing digital eye strain?
The American Academy of Ophthalmology recommends the 20-20-20 rule: for every 20 minutes of screen viewing, look away and focus on an object 20 feet away for at least 20 seconds. Make sure to blink when you do. If your eyes still feel dry, you can use a preservative-free artificial tear.

If screens truly don’t damage the eye, why do we sometimes hear medical recommendations to limit screen time?
For most adults, recommendations are made to avoid the discomfort of digital eye strain. However, this can be improved by occasionally looking away from a screen while working and using eye drops. There’s also a misconception out there that the blue light thrown off by screens can damage the eye. There is no evidence that blue light causes damage to the eye.

In fact, there is more blue light absorbed from indoor fluorescent lighting and sunlight than from cellphone screens. Where blue light can pose an issue is with a person’s sleep. In terms of your circadian rhythm, blue light is a stimulant. This means that screen time before bed can prevent you from getting a good night’s sleep.

What about recommendations for kids?
For children, experts recommend limiting screen time for a variety of reasons, none of which relate to eye damage.

The American Academy of Pediatrics recommends no screen time for kids under 2, and no more than one hour of screen time for kids between the ages of 2 and 5. The reason is primarily based on an increased link to attention-deficit/hyperactivity disorder (ADHD) in kids exposed to more than two hours of screen time a day.

There is also a concern with childhood obesity and myopia (nearsightedness). Increased screen time is generally associated with sedentary indoor activities and less sunlight. And recently, increased sunlight exposure has been linked to decreased risk for myopia in kids.

Given the abundance of devices we use for work, education, entertainment and communication, it can be a challenge to limit screen time for many of us. Yet if we are aware of the downsides of excessive use, we can develop healthy screen time habits.