What Is Computer Vision Syndrome?

As we enter the 21st century, the growing use of computers in the home and office brings with it an increase in health risks, especially for the eyes. One eye problem, called Computer Vision Syndrome (CVS), is afflicting more and more people who find themselves constantly in front of computer screens. While eye health professionals have yet to find CVS as a cause of any permanent eye damage, the pain and discomfort associated with the problem can affect workplace performance or the enjoyment of home activities. With a few preventative measures, however, the symptoms associated with CVS can be easily erased. The General Ophthalmology Service at Scheie Eye Institute offers many techniques for preventing CVS.

Causes of Computer Vision Syndrome

The main causes of Computer Vision Syndrome include an unsuitable environment and the improper use of eyeglasses or contact lenses. To prevent CVS, changes need to be made to improve these conditions.

Symptoms of Computer Vision Syndrome

Computer Vision Syndrome is the name given to eye problems caused by prolonged computer use including:

  • Eye irritation (Dry eyes, itchy eyes, red eyes)
  • Blurred vision
  • Headaches
  • Backaches
  • Neck aches
  • Muscle fatigue
  • Although CVS has not been found to cause any permanent damage to the eyes, its painful symptoms can affect performance at work and at home. Eye health professionals, though, have found several ways to prevent CVS from affecting computer users.

Diagnosis of Computer Vision Syndrome

Treatment at Penn

Penn recommends the following helpful hints that could be solutions to Computer Vision Syndrome.

With a few simple changes, the environmental causes of CVS can easily be eliminated. Some solutions to these environmental causes include:

Reducing glare and harsh reflections on the computer screen by modifying the lighting in the room, closing window shades, changing the contrast or brightness of the screen, or attaching a filter or hood to the monitor. This will not only help eyes focus better, but may also eliminate the need to squint while looking at the screen. The visor test can help determine if the current lighting in the room is a problem. The test is conducted by cupping hands over the eyes like a baseball cap to block the lights while looking at the monitor. If an improvement is immediately noticed, then lighting changes should be made.

Moving the computer screen to improve the comfort of the eyes. The screen should be at or just beyond an arm's length away (about 20 to 26 inches) to give the eyes a comfortable focusing distance. The screen should also stand straight in front of the face instead of off to the side to ease eyestrain. The center of the monitor should be about four to eight inches lower than the eyes to allow the neck to relax and to lessen the exposed surface area of the eye, which will reduce dryness and itching.

Placing reference materials as close to the screen as possible. This will lessen the need to constantly refocus the eyes as well as the need to swing the head back and forth between the materials and the monitor. Using a document holder beside the monitor will minimize head and eye movements and focusing changes, and will decrease muscle fatigue, headaches and eye strain.

Improving posture by using adjustable equipment to reduce strain on the back, neck, shoulders and eyes. Adjust the height of the chair so the knees are bent at a 90-degree angle with the feet flat on the floor or footrest. Sit straight against a backrest with the forearms on armrests and the elbows bent at a 90-degree angle. The keyboard and mouse should be located lower than the elbow and within easy reach of the hands. The head should be tilted slightly down while looking at the center of the computer screen.

Giving the eyes and body frequent breaks from computer work to reduce eye and muscle fatigue. Since prolonged computer use requires a person to sit in the same position for an extended period, taking time out to stand, stretch and look around will not only help muscles, but will also give the eyes a chance to relax. If the opportunity to get up for full breaks is not frequently available, then "mini" breaks will suffice by looking up from the computer into the distance about every 15 minutes. Frequent blinking or the use of eye drops, too, will keep eyes from drying out and feeling itchy.

Finding and improving other problems that may be affecting the eyes, including drafty, dry or dusty air. Try to keep air vents or drafts from blowing into the face and drying out the eyes. Low humidity or fumes in a room can also dry eyes out faster than usual. Dust, too, can irritate eyes as well as accumulate on the computer monitor, which will decrease the sharpness of the screen and may cause eyestrain.

Adjustments in Eyeglasses or Contact Lens Prescription

Almost 71 percent of those who have reported experiencing the symptoms of Computer Vision Syndrome wear eyeglasses or contact lenses. These people also report more eye, neck and back pain than people who do not use optical aids. These results show that improvements need to be made in the way that people use and wear their glasses and contact lenses.


A visit to an ophthalmologist to receive or update a prescription is the first step in improving the effectiveness of optical aids in eliminating the symptoms of CVS. Patients should be sure to include information on special lifestyle concerns, such as computer use, to help the doctor find the right prescription for their needs. With this in mind, the doctor may find that a person who does not normally need glasses should wear them when using a computer. Additionally, the ophthalmologist can diagnose whether another suspected disease is the cause of certain symptoms and recommend treatment options.

Eyeglasses wearers need to make sure that their glasses sit properly on their face. When glasses are fitted, the optical center (OC) of each lens is placed directly in front of the eyes. If the glasses slip down toward the nose, the OC shifts to below the center of the eyes. This decreases the power of the lenses, which blurs vision and makes eyestrain more prevalent. A slip also causes neck strain when one tilts their head up to compensate for the move of the OC. To prevent slippage, adjust the stems and nosepieces of the frames, or see a professional to refit the glasses.

Bifocal, trifocal, and progressive addition lens users need to be especially aware of the fit of their glasses. The nature of these vision prescriptions make it more difficult for the wearer to see things straight ahead and at an arm's length away, which is the suggested placement of a computer screen. Consequently, those who use these special optical aids report even more CVS-related symptoms, especially eye and neck strain and focusing problems. To reduce these symptoms, the height of a bifocal may need to be raised, the power of the lenses may need to be adjusted, or special glasses designed specifically for computer use may need to be prescribed by an ophthalmologist.

Contact Lenses

Contact lens wearers need to remember to blink while they work at their computer. Computer use results in a decrease of blinking to almost one third of normal, while the straight-ahead gaze needed to look at a screen exposes more of the eye to the air. Combined, this causes the eye to dry out and become itchy much faster than usual, especially when a contact lens is resting on the cornea. If frequent blinking is not enough to eliminate the dryness and itching, an ophthalmologist can prescribe eye drops made especially for contact lenses.

Penn Programs & Services for Computer Vision Syndrome

Computer Vision Syndrome

Prolonged computer use can cause eye problems. Get treatment information here.

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