Task Lighting at a VDT Workstation

Abstract

Two experiments on task lighting at a VDT workstation are described. In Exp. 1, 16 subjects entered random letters for 40 min in a general lighting condition and two task lighting conditions. The results for task lighting, although not statistically significantly better than general lighting, were promising so a second experiment was done.

In Exp. 2, general ceiling lighting was the control condition; there were 4 task lighting conditions. Eight subjects entered random letters for 16 h. Words/min did not differ significantly among the five conditions. Comfort was evaluated for the eyes, neck, back, hand-wrist and seat. Comfort did not vary significantly among conditions for the neck, back, hand-wrist or seat; it did vary for eyes. Subjective evaluation varied significantly for each of the 32 adjectives; ceiling lighting was preferred over task lighting and some task lighting conditions were preferred over others. The single adjective scale is recommended as being more sensitive than the typical paired semantic–differential scale.