Lighting
Bright fluorescents are to computer users’ eyes what a drip, drip, drip, is to the foreheads of Chinese water-torture victims.
They’re rude, persistent distractions.
And as with the water torture, the fluorescents’ victims may be captives of sorts. How many people can dictate the lighting in their companies’ offices? Many. But not all. So the letters and numbers on their screens, the facts they need to do their jobs, may compete with the glare beamed off the glass.
What’s more, the culprit needn’t be just the fluorescents that light so many American offices.
“The window with sunshine streaming in may still be a psychologically gratifying link with the outside world,” says Eisen, “but it spells plain eyestrain and perhaps headache for every VDT operator within range of the glare.” Even brightly painted walls can sin here.
So can glossy paper. In fact, any paper is bad in one over-powering way. The proper lighting level for paperwork is much higher than for computer work. And yet most computer operators have yet to see the much-touted paperless office. How do you keep eyes comfortable with both paper and computer screens?
Here are some possible solutions to the lighting problem:
1. Removing half the tubes from existing fluorescent fixtures. You’ll want, however, to make certain that some areas of the room aren’t still overlit while others are light starved. Be skeptical. This is the miser’s solution. If you can get away with it, fine. But don’t count on it. Remember, the women at the insurance company in New York say they still suffered glare afterward.
2. Parabolic fluorescent fixtures with baffles to keep the light out of the places where it can cause glare.
3. Parawedge louvers, which, according to Eisen, “have been particularly effective on a number[number] of newspapers.” Small plastic cells turn light downward, so that, ideally, you can barely notice it at desks just a few feet from the one you’re illuminating. “Light should be cut off,” Eisen suggests, “outside a line emanating at a forty-five-degree angle from the fixture.”
4. Desk and floor lamps. You might buy rheostats you can plug in between them and the outlet to adjust the light level. And be careful otherwise. Shield your lamps so they don’t glare off nearby computer screens. Properly used, however, they could be a godsend for people doing both computer work and paperwork.
5. Indirect lighting. The disadvantage is the expense. You may have to repaint walls and ceilings and pay for a consultant to select the right tones. Moreover, indirect lighting may be hard to install in rooms with ceilings lower than nine feet. Used well, however, this is one of the best solutions.
As a general rule, think about a lighting level between 300 and 500 lux—between 32 and 53 footcandles. A lux tells how much light is hitting a certain area, and 9.5 lux would equal 1 footcandle. For rough measurements you might borrow a good lightmeter from a photographer. Don’t aim directly at the light. Sample, instead, desk and computer surfaces, among others, though not the screens themselves. For more detailed measurements and advice, hire a consultant or call your state labor department. Make certain you‘re in touch with the consulting rather than the enforcement branch. Yes, any contact with officialdom has its risks. But they’re low here. And you’re strengthening your hand in labor relations by documenting your concern for your workers’ eyes.
In fact, before you place your order for lighting, ask if your supplier can run a test in your office. Or can you at least visit offices using the product?
Also, all along, worry about glare as well as lighting levels. You might try the mirror test suggested by a veteran ergonomics expert. Place a mirror over the face of a computer screen. Then you can see where the glare is coming from—which window, which lamp; for all you know, the source could be a brightly colored painting or a glassed-in print.
Try to rid your office of glare instead of using a filter. “I believe in avoiding a broken arm rather than putting a splint on it afterward,” says Harry Snyder. If you need a filter, however, here are possibilities:
1. Coatings or etching applied during manufacture of the video displays. They needn’t harm the viewing quality noticeably.
2. Coatings put on after manufacture. Generally, but not always, they don’t work out.
3. “Colored plastic panels and etched faceplates,” which, says Eisen, “have such damaging effect on brightness and clarity of the characters that they should be avoided.”
4. Micromesh filters, favored by German ergonomists. Eisen says U.S. opinion of them “is mixed. They do a good job of reducing reflections, but the mesh makes for a restricted viewing angle, absorbs some of the light from the display, and scatters some of the rest, degrading the image.”
5. Polarizing filters. They may reduce brightness and shorten tube life, since you must crank up the tube to compensate; at $100 or more, they are more expensive than the other add-ons. But they give you a better image than other filters. The contrast especially can be impressive.