When you work at a computer for any length of time, it's common to experience eye strain, blurred vision, red eyes and other symptoms of computer vision syndrome (CVS). This is because the visual demands of computer work are unlike those associated with most other activities.
If you're under age 40, eye strain or blurred vision during computer work may be due to an inability of your eyes to remain accurately focused on your screen or because your eyes have trouble changing focus from your keyboard to your screen and back again for prolonged periods. These focusing (accommodation) problems often are associated with CVS.If you're over age 40, the problem may be due to the onset of presbyopia — the normal age-related loss of near focusing ability. This, too, can cause CVS symptoms.What can you do? For starters, have a comprehensive eye exam to rule out vision problems and update your eyeglasses prescription. Studies show that even small inaccuracies in your prescription lenses can contribute to computer vision problems.*If your glasses are up-to-date (or you don't need prescription eyewear for most tasks) and you continue to experience eye discomfort during computer work, consider purchasing customized computer glasses. These special-purpose glasses are prescribed specifically to reduce eye strain and give you the most comfortable vision possible at your computer.
Why Computer Glasses?
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. Your optometrist or ophthalmologist can help you decide which lens design will best suit your needs for computer glasses.
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. For more details about anti-reflective coating and tints for your computer glasses, consult your eye care professional.