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 may 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.

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The 20-20-20 rule involves taking a 20-second break from looking at a screen every 20 minutes. During the break, a person focuses on an object that is at least 20 feet away, which relaxes the eye muscles.

The following methods can help put this rule into practice:

  • Set an alarm for every 20 minutes while working, as a reminder to take a break.
  • Judging a distance of 20 feet can be difficult. But looking at an object more than 20 feet away works just as well. When in doubt, aim for a longer distance rather than a shorter one.
  • Look out a window during the 20-second breaks, if there is one nearby. It may be easier to find a distant object outdoors.
  • Download an app developed to help people follow the 20-20-20 rule. According to the National Keratoconus Foundation, options include EyePro and Awareness.

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.

Little scientific research has tested the effectiveness of the 20-20-20 rule, but both the American Optometric Association (AOA) and the American Academy of Ophthalmology (AAO) 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.

In a small 2020 study, a group of patients at a university eye clinic were advised to follow 20-20-20 instructions. Twenty days later, self-reports showed no change in computer eye strain symptoms. But results of a clinical test, “tear break-up time,” indicated a significant reduction in dry eye.

Some studies indicate that taking short breaks allows the eye’s focusing muscles to relax. This may relieve eye strain.

Several symptoms can indicate eye strain, including:

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.

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

  • Use eye drops: A person blinks less than usual when using digital screens, and this can dry out the eyes. Artificial tears can be purchased at most pharmacies, as well as online. Contact lens users should check whether the product is suitable for use while wearing lenses. People with certain eye conditions may need to use preservative-free eye drops.
  • Choose glasses over contacts: Consider wearing glasses instead of contact lenses during lengthy periods of computer work. Contact lenses can make dry eyes worse.
  • Use a humidifier: Increasing humidity in a room that is too dry can improve dry eye symptoms. This can be done using a humidifier.
  • Reduce screen glare: Protective anti-glare screens can be applied to computers, phones, tablets, and eyeglasses, to prevent eye problems. Also, flat screens tend to have less glare than curved ones.
  • Check the screen’s location: The AAO recommends that a computer screen should be 25 inches (64 cm) from the eyes, about the length of a person’s arm. It is best to place the screen so that a person’s gaze looks slightly downwards.
  • Adjust the screen’s contrast and brightness: Change settings so that the screen is just bright enough to read the text without straining. The right contrast may change depending on the presence of sunlight.
  • Get regular eye checkups: Uncorrected vision problems are a major cause of strain. Regularly attending checkups will ensure that any changes to a person’s eyesight are addressed quickly.

These strategies can reduce eye strain related to using tablets, phones, and computers. Fortunately, most of them require little time or financial commitment.

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

In some cases eye strain can persist after a person has tried using the 20-20-20 rule and other methods of prevention. Anyone in this situation should see a doctor, who can check for underlying conditions such as uncorrected vision problems.

An 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.