Visual display unit workstation lighting

Abstract Two experiments determined preferred general and workstation illumination; workstation illumination was 350 lux. In experiment 1, 12 subjects were treated to 2 illumination sources, 6 task lighting conditions and 3 screen luminance conditions. Subjects preferred the indirect + direct illumination. Preferred task document brightness ranged from 190 to 890 nits. There were no screen character brightness differences. In experiment 2, 24 subjects were treated with a constant workstation illumination of 350 lux to 6 conditions (2 illuminations of the room wall and 3 illumination levels in the area ahead of the operator). In the area ahead of the operator, subjects preferred an illumination (770–820 lux) level doubling the workstation illumination over 420 and 1180 lux. Subjects also preferred increased brightness variability on the wall. For offices with VDUs, designers should not only plan for a mixture of indirect + direct lighting but also should consider the lighting of the workstation surroundings as well as the workstation.