According to the agency, workers receive over 85 percent of their information through their eyes, and when the lighting conditions are poor, that information runs a higher risk of being processed inaccurately.

Common poor-lighting complaints from workers include eyestrain, eye irritation, blurred vision, dry and burning eyes and headaches, but other issues including posture and overall safety can be impacted by poor lighting conditions as well. Poor lighting can mean anything from lighting that causes glare, to overly bright lights, improperly placed lights or dim lighting.

Posture becomes an issue with lighting when workers assume awkward positions in order to more clearly see the work, and safety issues arise when workers have problems visually determining the position of a tool or the shape or speed of machinery.

CCOSH offers some suggestions for improving lighting conditions in the workplace including using filters to diffuse overhead lighting, covering windows with adjustable blinds, and painting walls, floors and furniture with a matte finish.

Source: CCOSH Health and Safety Report, March 2003 (online)