Spending long periods looking at computer, phone, or tablet screens can strain the eyes. Using the 20-20-20 rule can help to prevent this problem.

The rule says that for every 20 minutes spent looking at a screen, a person should look at something 20 feet away for 20 seconds.

Following the rule is a great way to remember to take frequent breaks. This should reduce eye strain caused by looking at digital screens for too long.

In this article, we describe how to use the 20-20-20 rule effectively. We also discuss the research behind the rule and other tips for preventing eye strain.

How to use the 20-20-20 rule

20 20 20 rule can help eye strain
Following the 20-20-20 rule involves taking a 20-second break from looking at a screen every 20 minutes.

The 20-20-20 rule was designed by Californian optometrist Jeffrey Anshel as an easy reminder to take breaks and prevent eye strain, according to the Optometry Times.

When following the rule, a person takes a 20-second break from looking at a screen every 20 minutes. During the break, the person focuses on an object 20 feet away, which relaxes the eye muscles.

The following methods can help a person to put this rule into practice:

  • Set an alarm for every 20 minutes while working, as a reminder to take a break.
  • Download an app developed to help people follow the 20-20-20 rule. The ProtectYourVision and eyeCare apps are some examples.
  • Look out a window during the 20-second breaks. Judging a distance of 20 feet inside can be difficult, but focusing on a tree or lamppost across the street should work well.

Alternately, a person can benefit from closing their eyes for 20 seconds every 20 minutes. Also, remembering to blink can prevent dry eye by encouraging tear production.

Anyone who spends the day sitting should periodically get up and walk around, to prevent back and neck pains.

What evidence supports the 20-20-20 rule?

Little scientific research has tested the effectiveness of the 20-20-20 rule, but both the American Optometric Association and the American Academy of Ophthalmology recommend it as a way to reduce eye strain.

Results of a 2013 study involving 795 university students suggested that those who periodically refocused on distant objects while using the computer had fewer symptoms of computer vision syndrome, which include eye strain, watering or dry eyes, and blurred vision.

Symptoms of eye strain

Several symptoms can indicate eye strain, including:

  • eye watering
  • blurred vision
  • dry eyes
  • headaches
  • eye redness

Sitting in the same position for a long time has other harmful effects on the body. For example, it can cause neck, back, or shoulder pain.

Tips for preventing eye strain

Like the 20-20-20 rule, the following methods can help to reduce or prevent eye strain:

20 20 20 rule eye drops
Applying eye drops can help a person suffering from dry eyes, which can occur when using digital screens for long periods.
  • Using eye drops. A person blinks less than usual when using digital screens, and this can dry out the eyes. Drops or artificial tears can be purchased at most pharmacies, as well as online. Specialty eye drops are available for people who wear contact lenses. Preservative-free eye drops are best.
  • Change computer settings. Making text twice as large as usual can reduce eye strain. Reading black text against a white background is easiest on the eyes.
  • Reduce screen glare. Protective anti-glare screens can be applied to computers and eyeglasses, to prevent eye problems. Also, flat screens tend to have less glare than curved ones.
  • Adjust the screen’s contrast. Change settings so that the screen is bright enough to read the text without straining. The right contrast may change, depending on the presence of sunlight.
  • Get regular eye checkups. Poor eyesight is a major cause of strain. Regularly attending checkups will ensure that a person has an updated prescription when needed.

The strategies listed above require little time or financial commitment, but they can reduce eye strain related to using tablets, phones, and computers.


The 20-20-20 rule is an effective way to reduce eye strain caused by looking at digital screens for long periods.

If eye strain persists after a person has tried using the rule and other methods of prevention they should see a doctor, who can check for underlying conditions such as chronic dry eye.

The eye doctor may need to evaluate their vision and test the level of moisture in the eyes. When making recommendations, the doctor will take a person’s occupation and overall eye health into account.