What to know about computer vision syndrome

Computer vision syndrome (CVS) is the term for a group of eye and vision-related problems that develop following the prolonged use of devices with digital screens.

Devices such as computers, tablets, and smartphones put increased demands on a person’s visual system. Using these devices for extended periods without breaks can cause CVS symptoms, including eye strain and headaches.

In this article, we explain what CVS is and outline its causes and symptoms. We also provide tips on how to avoid CVS and when to see an optometrist.

What is it?

The extended use of devices with screens may lead to eye strain and headaches.
CVS describes a group of symptoms that occur following the prolonged use of devices with digital screens. Such devices include:

  • personal computers
  • laptops
  • tablets
  • smartphones

Common symptoms of CVS include eye strain and headaches. A person may also experience neck and shoulder pain as a result of sitting for long periods.

It is not clear how much time a person needs to spend looking at a digital screen to develop CVS. However, according to the American Optometric Association (AOA), longer periods of screen use seem to correlate with higher levels of discomfort.

Causes

Computer vision syndrome occurs as a result of prolonged digital screen use.

Digital screens cause a person’s eyes to work harder than normal. Several factors are responsible for this, including:

  • the screen content being less sharp or focused
  • poor contrast of the screen’s content against its background
  • reflections or glare bouncing off the screen

The following factors may also contribute to CVS:

  • viewing the screen in low light conditions
  • being too close to or too far from the screen
  • positioning the screen at an angle that causes eye strain
  • taking insufficient screen breaks

Together, these factors put greater demands on the eyes’ ability to track and focus. These demands are even higher for people who have minor uncorrected vision problems.

If the additional demands on the visual system occur over extended periods, a person may experience symptoms of CVS.

Symptoms

The symptoms of CVS may differ from one person to another. Some common symptoms include:

  • eye strain
  • dry and itchy eyes
  • blurry vision
  • double vision
  • difficulty focusing
  • nearsightedness, also called myopia
  • headaches
  • neck or shoulder pain and stiffness
  • backache

Treatment

The symptoms of CVS will usually go away after a sufficient break from screen use.

However, people who have underlying eye or vision problems will need to treat these problems to prevent future episodes of CVS. Some potential treatment options include those below.

Regular eye examinations

People who do not visit their optician regularly may have undiagnosed vision problems that worsen as a result of prolonged screen use. Others may be using outdated prescription glasses or lenses that are no longer effective in correcting their vision problems.

Regular visits to an optician can reduce the risk of CVS and other vision problems.

Vision therapy

Vision therapy is a form of therapy that aims to develop or improve a person’s vision. It involves the use of eye exercises to improve eye movement and focusing.

Vision therapy may be an option for people who continue to experience CVS and other vision problems despite wearing corrective glasses or contact lenses.

Laser eye surgery

Some people with underlying vision problems may be good candidates for laser eye surgery. This procedure uses lasers to reshape the surface of the eye so that it can focus more effectively.

Prevention

The best way to prevent CVS is to avoid long and uninterrupted periods of digital screen use. However, this is not an option for many people who work at a computer.

The AOA recommend following the 20-20-20 rule when working at a computer. Doing this involves taking a 20-second break every 20 minutes to view something that is 20 feet away. Following the 20-20-20 rule can reduce eye strain from digital screen use.

Other tips for preventing the symptoms of CVS include:

  • positioning the screen at the optimal distance, which will be about 20–28 inches from the eyes
  • positioning the screen at a comfortable angle, with the center of the screen 15–20 degrees below eye level
  • ensuring that there is adequate lighting
  • using an antiglare screen or changing the angle of the screen to avoid glare from lighting
  • remembering to blink regularly enough to avoid eye dryness
  • wearing glasses or lenses to correct any underlying vision problems, where necessary
  • sitting comfortably with both feet flat on the floor and support in place for the arms while typing
  • taking regular rest breaks

When to see an optometrist

In many cases, the symptoms of CVS will go away once a person has spent sufficient time away from digital screens.

To prevent future episodes of CVS, a person should take steps to improve their work environment and adopt healthful screen-management habits.

A person should visit their optician if they continue to experience CVS symptoms despite making the necessary changes to their screen use. Persistent symptoms can sometimes be a sign of an underlying eye condition that requires appropriate treatment.

Summary

Computer vision syndrome describes a group of symptoms that can arise as a result of prolonged screen use. Common symptoms of CVS include eye strain and headaches.

CVS can affect anyone who looks at a computer, tablet, or smartphone screen for long periods without breaks. However, it is particularly prevalent among people who have underlying vision problems.

The symptoms of CVS tend to subside once a person has taken a sufficient break from viewing digital screens. People can prevent future episodes by creating a comfortable work environment and adopting habits to maintain good eye health. Following the 20-20-20 rule is an effective way to reduce the risk of eye strain.

 

Source:

www.medicalnewstoday.com/articles/computer-vision-syndrome#summary

20/20/20 to prevent digital eye strain. (2016).
https://www.aoa.org/documents/infographics/SaveYourVisionMonth2016-1.pdf
Computer vision syndrome. (n.d.).
https://www.aoa.org/patients-and-public/caring-for-your-vision/protecting-your-vision/computer-vision-syndrome
Laser eye surgery and lens surgery. (2020).
https://www.nhs.uk/live-well/healthy-body/laser-eye-surgery/
Loh, K. Y., & Redd, S. C. (2008). Understanding and preventing computer vision syndrome.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4170366/
Tran, K., & Ryce, A. (2018). Laser refractive surgery for vision correction: A review of clinical effectiveness and cost-effectiveness.
https://www.ncbi.nlm.nih.gov/books/NBK532537/
Vision therapy. (2016).
https://aapos.org/glossary/vision-therapy


Computer Eye Strain – what to do

Computer Eye Strain: 10 Steps For Relief

With so many of us using computers at work, computer eye strain has become a major job-related complaint. Studies show that eye strain and other bothersome visual symptoms occur in 50 to 90 percent of computer workers.

These problems can range from physical fatigue, decreased productivity and increased numbers of work errors, to minor annoyances like eye twitching and red eyes.

Here are 10 easy steps you can take to reduce your risk of computer eye strain and other common symptoms of computer vision syndrome (CVS):

  1. Get a comprehensive eye exam.

Having a routine comprehensive eye exam is the most important thing you can do to prevent or treat computer vision problems. If you haven’t had an eye exam in over a year, schedule a visit with an optician.

According to the National Institute of Occupational Safety and Health (NIOSH), computer users should have an eye exam before they start working on a computer and once a year thereafter.

During your exam, be sure to tell your optician how often you use a computer at work and at home. Measure how far your eyes are from your screen when you sit at your computer, and bring this measurement to your exam so your eye doctor can test your eyes at that specific working distance.

  1. Use proper lighting.

Eye strain often is caused by excessively bright light either from outdoor sunlight coming in through a window or from harsh interior lighting. When you use a computer, your ambient lighting should be about half as bright as that typically found in most offices.

Eliminate exterior light by closing drapes, shades or blinds. Reduce interior lighting by using fewer light bulbs or fluorescent tubes, or use lower intensity bulbs and tubes. If possible, position your computer monitor or screen so windows are to the side, instead of in front or behind it.

Many computer users find their eyes feel better if they can avoid working under overhead fluorescent lights. If possible, turn off the overhead fluorescent lights in your office and use floor lamps that provide indirect incandescent or halogen lighting instead.

Sometimes switching to “full spectrum” fluorescent lighting that more closely approximates the light spectrum emitted by sunlight can be more comforting for computer work than regular fluorescent tubes. But even full spectrum lighting can cause discomfort if it’s too bright. Try reducing the number of fluorescent tubes installed above your computer workspace if you are bothered by overhead lighting.

  1. Minimize glare.

Glare on walls and finished surfaces, as well as reflections on your computer screen also can cause computer eye strain. Consider installing an anti-glare screen on your monitor and, if possible, paint bright white walls a darker colour with a matte finish.

Again, cover the windows. When outside light cannot be reduced, consider using a computer hood.

If you wear glasses, purchase lenses with anti-reflective (AR) coating. AR coating reduces glare by minimizing the amount of light reflecting off the front and back surfaces of your eyeglass lenses.

  1. Upgrade your display.

If you have not already done so, replace your old tube-style monitor (called a cathode ray tube or CRT) with a flat-panel liquid crystal display (LCD), like those on laptop computers.

LCD screens are easier on the eyes and usually have an anti-reflective surface. Old-fashioned CRT screens can cause a noticeable “flicker” of images, which is a major cause of computer eye strain. Even if this flicker is imperceptible, it still can contribute to eye strain and fatigue during computer work.

Complications due to flicker are even more likely if the refresh rate of the monitor is less than 75 hertz (Hz). If you must use a CRT at work, adjust the display settings to the highest possible refresh rate.

When choosing a new flat panel display, select a screen with the highest resolution possible. Resolution is related to the “dot pitch” of the display. Generally, displays with a lower dot pitch have sharper images. Choose a display with a dot pitch of .28 mm or smaller.

Flicker is not an issue with LCD screens, since the brightness of pixels on the display are controlled by a “backlight” that typically operates at 200 Hz.

If you see a lower refresh rate (e.g. 60 Hz) noted on an LCD screen, don’t worry — this refers to how often a new image is received from the video card, not how often the pixel brightness of the display is updated, and this function typically is not associated with eye strain.

Finally, choose a relatively large display. For a desktop computer, select a display that has a diagonal screen size of at least 19 inches.

 

  1. Adjust your computer display settings.

Adjusting the display settings of your computer can help reduce eye strain and fatigue. Generally, these adjustments are beneficial:

  • Brightness. Adjust the brightness of the display so it’s approximately the same as the brightness of your surrounding workstation. As a test, look at the white background of this Web page. If it looks like a light source, it’s too bright. If it seems dull and grey, it may be too dark.
  • Text size and contrast. Adjust the text size and contrast for comfort, especially when reading or composing long documents. Usually, black print on a white background is the best combination for comfort.
  • Colour temperature. This is a technical term used to describe the spectrum of visible light emitted by a colour display. Blue light is short-wavelength visible light that is associated with more eye strain than longer wavelength hues, such as orange and red. Reducing
  • the colour temperature of your display lowers the amount of blue light emitted by a colour display for better long-term viewing comfort.

For computers running on a Microsoft Windows operating system, display settings can be adjusted in Control Panel. For an Apple computer, display settings are found in Systems Preferences (in the Applications folder in Finder).

In some cases, the colour temperature of a desktop computer monitor is adjusted on the display itself.

You can adjust text size when using Internet Explorer, Firefox, Safari and other browsers, too. For example, in Firefox, you can enlarge an entire webpage by using the keyboard command Ctrl + as many times as you want, while Ctrl 0 makes everything normal-sized again. (Ctrl – makes everything smaller.) To enlarge only the text, use Alt V, then Z, then T. Then use Ctrl + again, and you’ll see just the text enlarging.

Each browser and email program has different commands for adjusting text size, so look through the menus to learn what they are. Or visit Google and search for how-tos there.

Many smartphones let you adjust text size. For example, on the iPhone 4, you simply open the Settings menu, then choose General, then Accessibility, then Large Text. Here you can choose a new font size for core applications such as Mail, Notes and Calendar. The font will also display in certain third-party applications.

Whatever type of digital screen you’re using, you’ll enjoy it more if you make the effort to adjust the view for your visual comfort. Don’t know how? Check the manufacturer’s website or look it up on Google.

  1. Blink more often.

Blinking is very important when working at a computer; blinking moistens your eyes to prevent dryness and irritation.

When working at a computer, people blink less frequently — about one-third as often as they normally do — and many blinks performed during computer work are only partial lid closures, according to studies.

Tears coating the eye evaporate more rapidly during long non-blinking phases and this can cause dry eyes. Also, the air in many office environments is dry, which can increase how quickly your tears evaporate, placing you at greater risk for dry eye problems.

If you experience dry eye symptoms, ask your eye doctor about artificial tears for use during the day.

By the way, don’t confuse lubricating eye drops with the drops formulated to “get the red out.” The latter can indeed make your eyes look better — they contain ingredients that reduce the size of blood vessels on the surface of your eyes to “whiten” them. But they are not necessarily formulated to reduce dryness and irritation.

To reduce your risk of dry eyes during computer use, try this exercise: Every 20 minutes, blink 10 times by closing your eyes as if falling asleep (very slowly). This will help rewet your eyes.

To ease eye strain, make sure you use good lighting and sit at a proper distance from the computer screen.

  1. Exercise your eyes.

lady-computer

Another cause of computer eye strain is focusing fatigue. To reduce your risk of tiring your eyes by constantly focusing on your screen, look away from your computer at least every 20 minutes and gaze at a distant object (at least 20 feet away) for at least 20 seconds. Some eye doctors call this the “20-20-20 rule.” Looking far away relaxes the focusing muscle inside the eye to reduce fatigue.

Another exercise is to look far away at an object for 10-15 seconds, then gaze at something up close for 10-15 seconds. Then look back at the distant object. Do this 10 times.

This exercise reduces the risk of your eyes’ focusing ability to “lock up” (a condition called accommodative spasm) after prolonged computer work.

Both of these exercises will reduce your risk of computer eye strain. Also, remember to blink frequently during the exercises to reduce your risk of computer-related dry eye.

  1. Take frequent breaks.

To reduce your risk for computer vision syndrome and neck, back and shoulder pain, take frequent breaks during your computer work day.

Computer Vision News

New Report on Digital Eye Strain

“Eye Overexposed: The Digital Device Dilemma” is The Vision Council’s latest report on digital eye strain.

With our constant exposure to digital devices, the document reveals that not only young adults, but children and older folks, too, are experiencing symptoms like eye strain, headaches, dry eyes, blurred vision and pain in the neck, shoulder and back.

Many workers take only two 15-minute breaks from their computer throughout their work day. According to a recent NIOSH study, discomfort and eye strain were significantly reduced when computer workers took four additional five-minute “mini-breaks” throughout their work day.

And these supplementary breaks did not reduce the workers’ productivity. Data entry speed was significantly faster as a result of the extra breaks, so work output was maintained even though the workers had 20 extra minutes of break time each day.

During your computer breaks, stand up, move about and stretch your arms, legs, back, neck and shoulders to reduce tension and muscle fatigue.

Check your local bookstore or consult your fitness club for suggestions on developing a quick sequence of exercises you can perform during your breaks and after work to reduce tension in your arms, neck, shoulders and back.

  1. Modify your workstation.

If you need to look back and forth between a printed page and your computer screen, this can cause eye strain. Place written pages on a copy stand adjacent to the monitor.

Light the copy stand properly. You may want to use a desk lamp, but make sure it doesn’t shine into your eyes or onto your computer screen.

Improper posture during computer work also contributes to computer vision syndrome. Adjust your workstation and chair to the correct height.

Purchase ergonomic furniture to enable you to position your computer screen 20 to 24 inches from your eyes. The centre of your screen should be about 10 to 15 degrees below your eyes for comfortable positioning of your head and neck.

  1. Consider computer eyewear.

For the greatest comfort at your computer, you might benefit from having your eye care professional modify your glasses prescription to create customized computer glasses. This is especially true if you normally wear contact lenses, which may become dry and uncomfortable during sustained computer work.

Computer glasses also are a good choice if you wear bifocals or progressive lenses, because these lenses generally are not optimal for the distance to your computer screen.

References & Notes >>

Blink rate, blink amplitude, and tear film integrity during dynamic visual display terminal tasks. Current Eye Research. March 2011. Computer Workstations. U.S. Department of Labor, Occupational Safety & Health Administration. Accessed on OSHA website. June 2010. Computer Ergonomics. U.S. Centers for Disease Control and Prevention. Accessed on CDC website. June 2010. About the Author:

Source:

Gary Heiting, OD, is senior editor of AllAboutVision.com. Dr. Heiting has more than 25 years of experience as an eye care provider, health educator and consultant to the eyewear industry. His special interests include contact lenses, nutrition and preventive vision care. Connect with Dr. Heiting via Google+.