Design Considerations
Last Update: October 27, 2010
Adjust text size: Decrease text size.Restore text size.Increase text size.

Visual Comfort

Lighting is for visual performance, but lighting design is also to provide comfortable seeing conditions. Individuals have differing tolerances to conditions causing discomfort. Those conditions that are universally considered uncomfortable are those with an excessive range of luminances in the field of view (glare) or instabilities in the general light output (flicker).

Glare may either reduce visual capability (Disability Glare) or cause discomfort (Discomfort Glare), which may be immediately apparent or become apparent over prolonged exposure. As is the case glare, flickers negative effects may cause immediate problems or be felt over time. Both issues are discussed in this section.

Discomfort & Overhead Glare
It is important to understand that there is not a clear-cut line between comfort and glare. For instance, many people will happily work away in a daylit space with a window, turning their backs to the sun and avoiding the glare while generally enjoying a cheerful space.
More »

Flicker & Strobe
Flicker is the result of the visible (direct or off-axis) inconstancy of lamp lumen output based upon the oscillation of the current. This is a sustained condition during normal lamp operation, and not an intermittent condition due to start-up or failure.
More »

Design Considerations

  =  Subscriber Content