Office Lighting

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Office Lighting

Appropriate workplace lighting is an essential component of an office environment since it can impact on comfort and performance. The consequences of inadequate lighting may range from a dreary and uninteresting working environment to one where visual discomfort and fatigue are conducive to eyestrain, headaches, poor posture and muscle fatigue.

Lighting problems can occur in any type of office environment but problems tend to be more common and severe for computer users. The reason for this is that offices in the past required high levels of illumination because typewriters, pens and pencils were the dominant tools and paper was the primary medium for information. Offices today however, which rely more and more on computers, generally do not require such high levels of illumination. Computer offices should have lower illumination levels if possible since high light levels can "wash out" out the image on a computer screen and make it harder to view. If light levels are decreased, task lighting (e.g. desk lights) can be used to provide additional light for hard copy tasks.

Glare and Reflections

Glare is a very common lighting problem. Glare is the sensation produced when the levels of light are sufficiently greater than the level to which the eyes have adapted. In extreme cases, such as oncoming car headlights at night, glare can be severe enough to impair vision temporarily. Fortunately, in most office situations, glare is less extreme. The usual effects of excessive glare in the office include eyestrain, visual fatigue or similar visual discomfort.

Light reflected from polished, shiny objects within the visual field can cause visual discomfort. Although reflections can affect both computer and non-computer tasks, computer users probably tend to experience the most significant impact of reflections due to the orientation and the large area covered by the convex shape of the computer screen. Light sources located above or behind the computer user can be reflected and visible on the monitor's screen.

Control of Glare and Reflections

Fortunately, there are a number of ways to control glare and reflections for both computer and non-computer users. The basic guidelines are:

i) reduce the intensity of the source; ii) reduce the size of the source; iii) move the source farther from the line of sight; and iv) increase the background luminance.

Some practical applications of these guidelines are:

position computer workstations between rows of overhead lights rather than directly below;

position computer workstations at right angles to windows (e.g. operator does not face window or have back to window);

utilize partitions to block light from windows and overhead lights;

ensure that windows have coverings such as venetian blinds or drapes so that light levels can be controlled (these coverings are also useful for controlling radiant heat from the sun which can contribute to air quality concerns);

request that the overall light levels be decreased, particularly in the vicinity ofcomputer stations -- contact Facilities and Services or Physical Plant;

parabolic louvres, baffles or filters can help reduce glare;

tilt the computer monitor slightly downward to reduce reflection from overhead lights; and

consider using a good quality anti-glare filter for the monitor to reduce glare and improve contrast.

These examples should serve as a guide for dealing with annoying glare and reflections in the workplace but it is important to note that, since each environment is unique and because individuals have different preferences or tolerances for light levels, it may be necessary to experiment to find the solution(s) for a given situation.