Computer vision syndrome or CVS is a group of eye and vision problems caused by the extended use of electronic devices. Sometimes people refer to CVS as digital eye strain. Computer monitors, smartphones, tablets, many types of E-readers, and laptop screens can all contribute to computer vision syndrome.

Many people working in offices spend over seven hours each day looking at a digital screen, and 59% of American adults report symptoms of CVS. Children can develop computer vision syndrome too; American children spend an average of three hours a day viewing electronic screens.


There are three categories of computer vision syndrome symptoms:

  • Ocular surface mechanism refers to the physical condition of the eyes. The most common ocular surface symptoms are a gritty or burning sensation, redness, itching, and watery or dry eyes.
  • Accomodative mechanism symptoms affect vision and include blurred vision, double vision, difficulty focusing, and presbyopia or farsightedness. Presbyopia occurs when the lens of the eye loses elasticity.
  • Extraocular mechanism symptoms affect areas other than the eyes. These symptoms include headaches, backaches, neck aches, and muscle fatigue.

redness, itching, watery eyes, headaches fizkes / Getty Images


Blue Light

Blue light is near the top of the visible light spectrum and very close to UV light. It is also referred to as high-energy visible or HEV light because it has short wavelengths. As recently as ten years ago, very few screens emitted blue light, but now it is a component of over 90% of digital devices. Blue light contributes to eye strain and suppresses the production of melatonin, a hormone that regulates the sleep cycle. Decreased melatonin may lead to insomnia and poor sleep, which, in turn, worsens symptoms of digital eye strain.

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Aggravating Factors

Several aggravating factors can increase the severity of computer vision syndrome, including poor lighting, glare on digital screens, poor posture, and undiagnosed or uncorrected vision problems. Viewing distance also contributes to CVS. The human eye naturally rests while staring 20 feet away. Phones, tablets, and computer screens are typically 18 to 24 inches from the eyes during use. Ciliary muscles in the eyes spasm while adjusting to such close viewing proximity. The spasms lead to headaches, blurred vision, and an inability to focus.

viewing proximity, spasms, blurred vision PRImageFactory / Getty Images


Uncorrected Vision Problems

Everyone is vulnerable to computer vision syndrome, but people with uncorrected vision problems, which force the eyes to work harder, have a higher risk of developing digital eye strain. Involuntary actions such as squinting put excessive strain on the muscles around and behind the eyes. Appropriate eyeglasses or contact lenses alleviate this stress. Children and teenagers should see an eye doctor at least once a year, and adults over the age of 18 should make an appointment every two years.

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Diagnosing Computer Vision Syndrome

Optometrists or ophthalmologists diagnose computer vision syndrome with a comprehensive eye examination and detailed patient history. Eye doctors ask patients about general health problems, medications, electronic device usage, and any relevant environmental factors. The examination measures visual acuity and refraction, enabling doctors to identify the best lens to compensate for refractive errors such as nearsightedness, farsightedness, or astigmatism.

diagnose, eye examination, refraction, acuity zoranm / Getty Images


Visual Therapy

Vision therapy is a visual training program to correct problems with eye coordination and focus. Long-term digital eye strain can interfere with focusing while away from the computer. Previously existing issues with eye coordination can also increase the severity of computer vision syndrome. The patient performs a series of exercises under medical supervision. Participants frequently practice at home between visits. The exercises train the eyes and brain to work together, interpret visual information effectively, and improve visual ability, to reduce stress on the eye muscles.

vision therapy, exercises, brain, coordination Goodboy Picture Company / Getty Images


Improve Lighting

Overly bright sunlight and indoor light aggravate eye strain. Ambient lighting during computer use should be approximately half as bright as necessary for reading from paper or taking notes by hand. Close curtains, shades, or blinds to block excess exterior light. Position computer screens so windows are off to the side instead of directly in front or behind the screen. Use fewer light bulbs, or switch to varieties with a lower light output. Shut off overhead fluorescent lights entirely, if possible, and use floor lamps to provide indirect LED lighting instead. If fluorescent lighting is unavoidable, full-spectrum bulbs that mimic the natural light spectrum are best. This is not an ideal solution because full-spectrum fluorescent lighting is still too bright, but the improvement could reduce CVS symptoms.

fluorescent, LED lighting, floor lamp Carsten Koall / Getty Images


Reduce Glare

Glare comes from light reflected off walls or glossy surfaces, as well as reflections on the computer screen itself. Reducing glare from digital screens helps avoid or reduce the severity of computer vision syndrome. Bright white walls reflect more light than darker colors. Paint walls in darker shades and use a matte finish to reduce glare. Consider installing matte screen filters on computer monitors, tablets, laptops, or phones. Move lamps and other lights to prevent them from reflecting off screens, or rearrange desks if the issue comes from an immovable source.

glare, reflective, visible, matte, filters Delmaine Donson / Getty Images


20-20-20 Rule

The optometrist Jeffrey Anshel created the 20-20-20 rule, which states that a person should look at something 20 feet away for 20 seconds at 20-minute intervals while using a digital screen. Frequent breaks reduce the symptoms of computer vision syndrome.

Set an alarm for every 20 minutes while working or playing on a computer, or download an app that prompts regular breaks. Look out the window for 20 seconds and focus on a tree or lamppost that is approximately 20 feet away.

Many people blink less frequently than normal while viewing digital screens. Infrequent blinking dries out the eyes. Consider using saline eye drops during breaks. Stretching or walking around at 20-minute intervals also helps alleviate CVS symptoms such as back or neck aches.

20 rule, seconds, minutes, break PeopleImages / Getty Images


Use Proper Equipment

Gunnar glasses were designed especially for gamers, who spend hours at a time staring at computer screens. They have tinted yellow lenses to counteract blue light and provide a small amount of magnification for easier reading. Gunnar glasses are available in a variety of styles and prescriptions. Stop using old computer monitors and other screens with cathode-ray tubes or CRT. CRT screens flicker and contribute to digital eye strain and fatigue. Choose flat-panel, anti-reflective LED screens, instead. E-Readers with eInk or electronic ink technology imitate printed paper. They provide a high contrast between the text and background to ease digital eye strain, and are lit differently than computer and table screens.

CRT, replace, flat-panel, anti-reflective screen adventtr / Getty Images


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