COMPUTER VISION SYNDROME
Computer Vision Syndrome, also referred to as Digital Eye Strain, describes a group of eye and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use. Many individuals experience eye discomfort and vision problems when viewing digital screens for extended periods. The level of discomfort appears to increase with the amount of digital screen use.
The average American worker spends seven hours a day on the computer either in the office or working from home. March is Save Your Vision Month and the American Optometric Association is working to educate both employers and employees about how to avoid digital eye strain in the workplace. To help alleviate digital eye strain, follow the 20-20-20 rule; take a 20-second break to view something 20 feet away every 20 minutes.
The most common symptoms associated with
Computer Vision Syndrome (CVS) or Digital Eye
neck and shoulder pain
These symptoms may be caused by:
glare on a digital screen
improper viewing distances
poor seating posture
uncorrected vision problems
a combination of these factors
The extent to which individuals experience visual symptoms often depends on the level of their visual abilities and the amount of time spent looking at a digital screen. Uncorrected vision problems like farsightedness and astigmatism, inadequate eye focusing or eye coordination abilities, and aging changes of the eyes, such as presbyopia, can all contribute to the development of visual symptoms when using a computer or digital screen device.
Many of the visual symptoms experienced by users are only temporary and will decline after stopping computer work or use of the digital device. However, some individuals may experience continued reduced visual abilities, such as blurred distance vision, even after stopping work at a computer. If nothing is done to address the cause of the problem, the symptoms will continue to recur and perhaps worsen with future digital screen use.
Prevention or reduction of the vision problems associated with Computer Vision Syndrome or Digital Eye Strain involves taking steps to control lighting and glare on the device screen, establishing proper working distances and posture for screen viewing, and assuring that even minor vision problems are properly corrected.
Products That Treat Computer Vision Syndrome
Computer glasses differ from regular eyeglasses or reading glasses in a number of ways to optimize your eyesight when viewing your computer screen.
Computer screens usually are positioned 20 to 26 inches from the user's eyes. This is considered the intermediate zone of vision — closer than driving ("distance") vision, but farther away than reading ("near") vision.
Most young people wear eyeglasses to correct their distance vision. Reading glasses are prescribed to correct near vision only. And bifocals prescribed for those over age 40 with presbyopia correct only near and far. Even trifocals and progressive lenses (which do have some lens power for intermediate vision) often don't have a large enough intermediate zone for comfortable computer work.
Without computer eyeglasses, many computer users often end up with blurred vision, eye strain, and headaches — the hallmark symptoms of computer vision syndrome. Worse still, many people try to compensate for their blurred vision by leaning forward, or by tipping their head to look through the bottom portion of their glasses. Both of these actions can result in a sore neck, sore shoulders and a sore back.
Though they sometimes are called "computer reading glasses," it's best to call eyewear designed specifically for computer use "computer glasses" or "computer eyeglasses" to distinguish them from conventional reading glasses. Computer glasses put the optimum lens power for viewing your computer screen right where you need it for a clear, wide field of view without the need for excessive focusing effort or unhealthful postures.
University research also shows computer eyewear can significantly increase worker productivity.
Lens Designs for Computer Eyewear
Many special purpose lens designs work well for computer glasses. Because these lenses are prescribed specifically for computer use, they are not suitable for driving or general purpose wear.
The simplest computer glasses have single vision lenses with a modified lens power prescribed to give the most comfortable vision at the user's computer screen. This lens power relaxes the amount of accommodation required to keep objects in focus at the distance of the computer screen and provides the largest field of view.
Single vision computer glasses reduce the risk of eye strain, blurred vision and unnatural posture that can cause neck and back pain, and can be used comfortably by young and old computer users alike.
Another popular lens design for computer glasses is the occupational progressive lens — a no-line multifocal that corrects near, intermediate, and, up to a point, distance vision. It has a larger intermediate zone than regular progressive lenses for more comfortable vision at the computer. But this leaves less lens area for distance vision. So these lenses are not recommended for driving or other significant distance vision tasks.
Other lenses used for computer glasses include occupational bifocal and trifocal lenses. These lined multifocal lenses have larger zones for intermediate and near vision than regular bifocals and trifocals, and the position of the intermediate and near zones can be customized for your particular computer vision needs.
Lens Coatings and Tints
For maximum viewing comfort, the lenses of your computer glasses should include anti-reflective coating. Sometimes called anti-glare treatment, anti-reflective (AR) coatings eliminate reflections of light from the front and back surfaces of your lenses that can cause eye strain.
Some eye doctors recommend adding a light tint to computer glasses to reduce glare caused by harsh overhead lighting and to enhance contrast. Tinted computer lenses also are recommended to block short-wavelength, "blue" light emitted from computer screens that is associated with glare and eye strain.
Information about computer vision syndrome provided by the American Optometric Association and All About Vision.