Lighting is often referred to as one of the top three ergonomic concerns for office workers, yet is generally ignored when it comes to evaluating office workstations. Past American National Standards Institute (ANSI) lighting standards only concentrated on adequate lighting levels for normal reading and writing tasks. This changed in the early 1980s with the increased use of computers in the workplace. Today, most common work tasks have become computer-based, with computer screens being the primary focus for work. Paper files are being phased out in favor of scanned documents viewable primarily on computer screens.

Many users complain of headaches, nausea, and visual fatigue as a result of the visual demands associated with computer use. Poorly adjusted computer screens usually results in the user adjusting their posture or position, oftentimes resulting in neck, shoulder, or back strain. And while these types of injuries can be quite complicated in their pathology and treatment, there are several simple strategies for reducing ergonomic risk due to lighting.

Ballasts

Virtually all offices are lit using overhead fluorescent systems controlled by regulating ballasts located in each fixture. Inefficient older electromagnetic ballasts appear to be a causational factor in many of the complaints noted above. With a lifespan of about 10-years, these older ballasts emit a subtle flicker and hum. A simple and cost-effective solution is to replace older electromagnetic ballasts with newer, energy-efficient, high frequency solid-state ballasts. Similar in cost as the older electromagnetic ballasts, solid-state ballasts effectively eliminate flicker and hum, and typically last 20 or more years.

Glare

There are many sources of glare including window light, reflected light from a standard downlighting system, poorly located task lights, and reflections from glossy walls. Since glare makes computer viewing difficult, most people will try to adjust either themselves or the monitor screen in order to see better, which can frequently result in awkward postures that may contribute to musculoskeletal discomfort. Some suggestions for reducing or eliminating glare include:

• Install an indirect lighting system where light is projected evenly onto the ceiling and then reflected more softly onto the work surface. The result is shadowless and glare-free ambient lighting.
• Most offices today are overlit. About 30 foot-candles of light are recommended for computer workstations. It might be worthwhile to have a lighting expert come in to evaluate an office lighting system.
• Install dimmable electronic ballasts and appropriate switches so that users can control their immediate lighting environment. Lower settings will also result in increased energy savings.
• Window coverings such as blinds and window film can control excessive light levels from outside sources.
• Adjust task lights to eliminate glare on the computer screen.

For more detailed information on lighting, see the article titled "An Ergonomic Primer on Office Lighting".