Your eyes may feel tired or irritated after focusing intensely on activity like viewing a computer screen, reading a book, or driving a car for a long period of time. This is known as eyestrain.

Eyestrain is a common condition. It’s becoming even more frequent in this digital age. Eyestrain caused by the use of digital devices like computers, smartphones, and tablets is better known as computer vision syndrome or digital eyestrain.

Generally, eyestrain can be treated with simple, noninvasive methods. Prolonged eyestrain or eye irritation may be a sign of something more serious and should be discussed with your doctor.

Eyestrain may occur after focusing on one particular task for an extended period of time. Some symptoms of eyestrain include:

One of the biggest causes of eyestrain is the daily use of digital screens for several hours at a time. The Vision Council reports that 87 percent of those in the United States use one or more digital device for more than two hours a day. And the use of digital devices is not exclusive to adults. The same report states that 76.5 percent of American children are looking at screens for more than two hours a day. These children may experience the effects of eyestrain or other conditions as a result of this digital device exposure.

Other common causes of eyestrain include:

  • focusing on a single task for a long length of time, such as driving or reading
  • being in an inadequately lit environment, either too dim or too bright
  • feeling stressed or tired
  • experiencing poor vision or eye problems like dry eyes

Some causes specific to digital eyestrain are:

  • maintaining poor posture when viewing a digital device
  • failing to blink as often as normal
  • holding a digital device too far or too close to your eyes
  • being exposed to extended amounts of blue light, which is the light commonly emitted from digital devices
  • viewing a screen that doesn’t have properly adjusted lighting

There are some simple things you can do to help prevent eyestrain. Some of them you can even start doing today.

1. Look away frequently, or the 20-20-20 rule

Often eyestrain occurs when you engage in a single activity for too long a period of time without a break. You should shift your focus to something other than the activity every 20 minutes. What you focus on should be 20 feet away, and you should look at it for at least 20 seconds. This is known as the 20-20-20 rule.

You should not only look away every 20 minutes, but also make sure to turn away from an intense activity for several hours during the day. If you have to work at a screen or drive a long distance for multiple hours, make sure to balance that activity with others that demand different uses of your eyes. For example, take a walk outside in the natural light during your lunch break if you’ve spent the whole morning working on a computer.

Read more: 10 things that happen when you sit down all day »

2. Position your screen

Make sure you’re looking at your digital device at the correct distance and in the proper position. The screen should be a few feet away from your eyes, or about arm’s length. You should view the screen at the level of your eyes or slightly below them. This goes for handheld digital devices, too: They should be read at below eye level.

Another handy tip for digital devices is to enlarge the text on the screen to best suit your comfort level. You can likely adjust text size in the settings of your device.

3. Find the right light

Lighting can cause eyestrain. It can either be too dim or too bright, depending on the activity. Light should come from behind you if you’re focusing intensely on something like reading. Dimming the lights may help reduce eyestrain when watching TV.

Make sure the screens that you’re viewing are adequately lit as well. Adjust the brightness as needed. Glare can contribute to eyestrain, so try shading windows or using filters to reduce glare on your digital device.

4. Multitask correctly

It’s common to need to use printed matter or other materials when working on a computer. For example, you may need to transcribe a form or notes. If you have to refer to documents and such while using your computer, you should position them to avoid having to move your eyes, neck, and head too frequently. A document stand can help you place materials between your keyboard and your monitor, resulting in less eyestrain.

5. Use eye drops

Intense focus, particularly when viewing a screen, can result in a dramatic reduction in how many times you blink per minute. When you blink less, your eyes can get dry and irritated. You can resolve this with the use of eye drops like artificial tears. You can also try to blink more often when using a screen, which can prevent the symptom from occurring.

6. Check the air

You may find that you spend time in a place that has poor air quality. Dry or polluted environments and places with fans and heating and cooling units may cause eyestrain. You may want to:

  • improve the air with a humidifier
  • turn down the heating and cooling system
  • relocate to a spot that doesn’t have the same air issues

7. Wear proper eyewear

Work with your doctor to determine if you need special eyewear to reduce eyestrain. You may even need specialized lenses, devices, or eye therapy for the activity that causes strain. Certain coatings and tints for lenses may help your eyes. Or you may find that you need to cut the time you wear contact lenses to help rest your eyes.

8. Reduce time spent on a single activity

A simple way to avoid eyestrain is to limit the time you’re exposed to a single activity that requires intense focus. Try to spend less time on digital devices.

In many cases, changes like the ones noted previously are all you’ll need to make to treat eyestrain. If you experience eyestrain that’s severe or lasts a long time, discuss the condition with your doctor. You may need corrective lenses, or it could be a symptom of a more serious condition.

Spending a great amount of time on a focused activity puts you at risk for eyestrain. You may have an increased risk for eyestrain if you work on computers as part of your job. Children who spend lengthy amounts of time on digital devices may also experience eyestrain or other conditions, such as irritability or behavior problems.

When you engage with digital devices for a lengthy amount of time, you expose yourself to blue light, which may be harmful to your eyes in the long term. Blue light can cause:

  • problems with your retina
  • cataracts
  • age-related macular degeneration
  • sleep disturbances

Specialized lenses can reduce your exposure to blue light.

Maintaining your eye health is key to reducing more serious vision problems in the future. You should see your doctor annually to have your eyes checked, especially if you experience frequent or long-lasting eyestrain. If you find you have symptoms of eyestrain, implement some methods to reduce eyestrain or prevent it altogether. If you find that these approaches don’t help your eyestrain, consult your doctor.