Computer Vision Syndrome: The Eyes Have It?
Do you have dry, irritated eyes, eyestrain, blurry vision, and headaches after extensive hours at the computer? You may be suffering from an ocular condition called computer vision syndrome, or CVS. It is estimated that over 175 million people suffer from CVS. And this does not include the growing number of children developing eye problems related to the use of computer and portable electronic devices.
CVS is caused by the constant effort it takes for your eyes to focus when viewing a computer screen. Unlike printed text in a book, the images on a computer screen are made up of small characters called pixels. Since pixels do not have sharply defined edges or background contrast, your eyes cannot focus the images automatically. Continually, your eyes drift out to their natural resting state and then strain to regain focus on the screen. This constant refocusing overworks your eye muscles and, thus, causes eyestrain symptoms. Elements of screen contrast, resolution, flicker, and glare further contribute to CVS.
To help improve and prevent computer vision symptoms, it is important to get regular eye examinations and make basic changes to your computer workstation.
- Get an eye exam. Regular eye examinations can help to prevent or reduce the development of visual symptoms associated with CVS. Uncorrected visual problems (farsightedness, astigmatism, and presbyopia) and inadequate eye focusing or eye coordination abilities contribute to CVS. According to the National Institute of Occupational Safety and Healthy (NIOSH), computer users should have an eye exam before they start working on a computer and annually thereafter.
- Modify your working environment. The optimal position for your computer monitor should be at about 15 to 20 degrees below eye level (about 4 or 5 inches) as measured from the center of the screen and 20 to 28 inches from the eyes. When working with reference materials, use a document holder. A document holder should be positioned at the same distance and height as the computer monitor to prevent the eyes from having to change focus. It will also help eliminate extra movement of the neck to look down at a document on a desk top.
- Use proper lighting and minimize glare. Most offices are equipped with too much light such as overhead fluorescent lights that can cause glare. The American Optometric Association (AOA) recommends removing half the bulbs from office ceiling fixtures or using desktop lamps instead of overhead light. Replacing fluorescent bulbs with full-spectrum or incandescent bulbs can alleviate glare and eyestrain. Use blinds or drapes on windows to eliminate exterior bright light. The display screen should be positioned at right angles to windows and light sources to minimize reflected light. Applying an anti-glare screen over computer monitors can further reduce glare. Anti-reflective coating on eyeglasses lenses can also minimize glare issues.
- Take frequent breaks. The 20/20/20 rule: For every 20 minutes of computer viewing, look 20 feet away for 20 seconds to reduce eye fatigue.
- Blink more often. The average person blinks 10 to 15 times per minute. The blinking rate of computer users is reduced by 60%. This reduction in blinking rate contributes to poor tear production, therefore, resulting in dry eyes. To minimize dry eyes, make an effort to blink often or use artificial tears to moisturize the eyes.
- Computer glasses. Specially designed computer glasses can aid in relieving the symptoms of CVS. Single vision computer glasses with a modified lens power designed specifically for the user’s computer distance can be prescribed. Occupational progressive lens, a no-line multi-focal with larger intermediate and near areas than a regular progressive, can be customized for optimal computer use. Ask your optometrist which lens design is the most suitable option for you.