Screen Time and Tired Eyes: The Simple 20-20-20 Rule
Why phones, tablets and computers can leave your eyes tired and dry, and easy ways to stay comfortable, starting with the 20-20-20 rule.
Maybe you read the news on your phone, video chat with the grandchildren, or look up recipes on a tablet. Screens are part of daily life now.
If your eyes feel tired, dry or achy after a while, you're not alone. The good news is that this kind of discomfort is common, and simple habits can help.
First, some reassurance
Many people worry that screens "ruin" their eyes. The American Academy of Ophthalmology says this is not true. Screens don't cause lasting damage, but staring at them for a long time can make your eyes uncomfortable.
The Academy also explains that this strain is no different from what you might feel after reading, writing or sewing for a long stretch.
What digital eye strain feels like
You might notice:
- Tired, achy or sore eyes
- Dry, burning or stinging eyes
- Blurry vision that comes and goes
- Watery eyes
- A headache, or a stiff neck and shoulders
Why screens tire your eyes
You blink less
Blinking spreads a fresh layer of moisture across your eyes. The American Academy of Ophthalmology notes that we normally blink about 15 times a minute, but only about 5 to 7 times a minute while looking at screens. Fewer blinks means drier eyes.
Your focus stays locked
When you look at something close for a long time, the eye's focusing system keeps working without a break.
Glare and brightness
A screen that's much brighter or darker than the room around it makes your eyes work harder.
The 20-20-20 rule
This is the easiest habit to remember:
- Every 20 minutes
- look at something at least 20 feet away
- for at least 20 seconds.
The American Academy of Ophthalmology and the National Eye Institute both recommend this simple break.
Twenty feet is about the length of a living room, or the distance to a tree outside your window.
Ways to remember it
- Look up whenever you finish an article or a page.
- Set a gentle timer on your phone.
- Rest your eyes at every TV commercial break.
- Keep a plant or a picture across the room to look at.
More ways to keep your eyes comfortable
Blink on purpose
Make a habit of blinking fully a few times whenever you think of it. A small sticky note that says "blink" can help.
Match your screen to the room
The American Academy of Ophthalmology suggests adjusting screen brightness to match the light around you, and increasing the contrast.
Mind the distance
For a computer, the Academy recommends sitting about 25 inches away, about an arm's length, with the screen a little below eye level so you look slightly down.
Make the words bigger
On a phone or tablet, you can increase the text size in the settings. Bigger letters mean less squinting.
Watch the air
The American Academy of Ophthalmology's eye strain article suggests keeping air vents from blowing in your face. A humidifier can help if the room is dry.
Check your glasses
An outdated prescription can make strain worse. If you use a computer often, ask your eye doctor whether glasses made for screen distance might help you.
What about blue light?
You may have seen glasses or screen filters that claim to block blue light.
The American Academy of Ophthalmology says there is no scientific evidence that blue light from screens damages the eyes. It does not recommend special blue light-blocking glasses for computer use. In fact, the sun gives off far more blue light than any screen.
Blue light can affect sleep, though. Screens late at night may make it harder to fall asleep. The Academy suggests limiting screen time in the two to three hours before bed, or using night mode in the evening.
A simple screen routine
- Before you start: Turn up the text size and adjust the brightness.
- While you read: Follow the 20-20-20 rule and blink often.
- Every hour: Stand up, stretch and look out a window.
- In the evening: Put the phone down a couple of hours before bed.
When to talk to your eye doctor
Most screen-related discomfort eases with rest. But please see your eye doctor if:
- Your eyes stay red, blurry or watery, or become sensitive to light or painful. The American Academy of Ophthalmology recommends seeing an ophthalmologist in these cases.
- Strain continues even after you adjust your screen and take breaks.
- You think your glasses aren't working as well as they used to.
- You're due for a dilated eye exam.
Describe when your symptoms happen and how long they last. That helps your doctor find the cause.
