I’ve finally got computer glasses, after years of gradually increasing difficulty focusing at mid-range between distance and close-up vision. My optometrist first suggested bifocals back in ’02, but I resisted. In hindsight, this was not my wisest decision. My reasoning wasn’t vanity; I was getting along reasonably happily with single vision lenses, and didn’t want to complicate my life.
However, difficulty reading my computer screen went critical last spring when I downsized from a 17″ PowerBook (s aapl) to a 13″ unibody MacBook. I love the MacBook’s bright, sharp LED backlit display, but it’s smaller both in resolution and physical dimensions than my old machine. Happily, the computer glasses make reading the new display easier, clearer and more squint- and strain-free than the 17″ display with my old glasses. As expected, I find it tedious to have to switch spectacles when I’m not at the computer or reading, but having just turned 58, I guess making some concession to age is inevitable.
Computer glasses have prescription lenses allowing you to focus without strain on a computer screen, which is farther away than you would normally hold reading material (or should be, anyway — at least 20 to 26 inches from the user’s eyes is the standard recommended distance). A “task-specific” analog would be piano glasses for musicians. Regular bifocals aren’t really that helpful for computer work, although some folks find the transition area between reading and distance views with progressive bifocals provides some mid-range support that works for them. My new lenses are bifocals, but with only mid-range in the upper plane with the lower part of the lens for regular reading and other close work (a variant known as “occupational bifocal”), so I still need single vision regular glasses for distance work — watching TV, driving and just normal seeing.
Another option is single-vision mid-range lenses — pure “computer glasses,” but eyeglass-wearers will need another pair of specs., since both distant objects and reading materials closer than the computer screen will be blurred.
A “do-all” solution is trifocal glasses with three lens planes combining an upper segment for distance vision, a lower/bottom one for close work, and a third one for mid-range or screen distance in between. The downside of trifocal lenses is limited continuity of vision and peripheral distortion greater than with bifocals or single vision lenses. A trifocal variant is occupational “readables” with a relatively larger center zone for mid-range computer distance and proportionately smaller lower and upper zones for reading/close work and focusing at about 10 feet for “room-type vision” respectively. However, “readables” are not intended for driving and such because they don’t support true distance focus.
With multi-focal lenses there’s also the choice between Progressive Addition Lenses (PAL) which eliminate the hard lines between the two or three segments, or conventional multifocals with lines. I like clear distinctions so went with regular lined bifocals, but that’s personal preference. Your eye specialist (optometrist or ophthalmologist) can consult and advise on which is best for you. My optometrist uses single vision computer glasses himself.
By around age forty or so, ability to focus on close objects begins diminishing (a phenomenon known clinically as “presbyopia”). Most forty-plus folks require vision correction for reading or performing other near tasks. I fudged it for 18 years after that using a “poor man’s bifocals” mode: holding reading materials close and peering over the top of my distance lenses.
Even younger users who spend a lot of time in front of computer screens may find greater comfort and fewer eyestrain issues by wearing computer glasses for screen viewing. Reportedly, growing evidence indicates that the stress focusing on mid-range or near objects over long periods can induce an effect “accommodative spasms” which may in turn result in increased or premature short-sightedness. Wearing computer glasses decreases accommodative effort and can help prevent or delay vision deterioration.
Computer Vision Syndrome
The growing number of people having trouble in this context is large enough that a new category of visual disorder called “computer vision syndrome” (CVS) has been described referring to computer-related vision problems, replacing the vaguer “eyestrain.” The most common CVS symptoms include headaches, visual focusing difficulties, burning, tired, aching, or dry eyes, double or blurred vision, light sensitivity, and neck and shoulder pain.
Aside from visual correction, other strategies that can help minimize and alleviate CVS include lowering light levels in computer workstation environments; getting anti-reflective and or Ultraviolet (UV) coatings on eyeglass lenses to reduce fatiguing glare and blue component light; and taking regular breaks from staring at the screen. Lens tints provide enhanced comfort for some users, although I don’t like them personally. Workplace environmental humidity can play a role as well.
Having a proper chair at correct height to support ergonomic posture with back straight and shoulders back, and using a laptop stand with an external keyboard and pointing device when working with portable machines at your desk to elevate the display to a higher viewing level help minimize eye and neck strain. Getting a bigger monitor can be beneficial too, even for laptops pulling desktop substitute duty, and monitors should be situated directly in front of the user — not at an angle or off to one side, at roughly arm’s length from your eyes.
One inhibition to getting computer glasses may be cost, especially in this recession. Prescription eyeglasses acquired through tradition channels tend to be expensive, but there are alternatives. I got my new specs from Goggles4U.com. They have nice light titanium frames, anti-scratch and UV coatings and prescription lenses, all for the grand total of $63.99 delivered to my door here in Nova Scotia, arriving from Pakistan in a charmingly hand-stitched and addressed cloth bag with wax seals, and including a hard case, cleaning cloth, and a handy-dandy little screwdriver tool for maintenance.
Do you suffer with Computer Vision Syndrome? Have you tried computer glasses?