Illuminance levels must be adequate for the task to prevent visual fatigue.
Problems associated with lighting are not always given a high priority. This may be due to a lack of understanding of the subject or a lack of information regarding the potential consequences of poor or inappropriate lighting.
‘Normal’ lighting in a workplace is not directly associated with health effects other than possible eyestrain and headaches. In some instances poor lighting may be a contributory factor to ‘office sickness’ or ‘sick building syndrome’.
There are several indicators which could suggest that a problem with lighting may exist. These could include squinting at an object, looking too closely at objects or script or needing to shade the eyes to see.
Indirect, inadequate or inappropriate lighting, can results in accidents with far more serious consequences. Changing the layout of a factory or other workplace, without altering the lighting can leave some areas in an unacceptable shadow.
Lighting is not only about intensity. Other related factors maybe more significant in specific situations:
- Glare from reflective surfaces
- Orientation of light fitting
- Type of lighting
- Location of lights with respect to the task and operators
- Movement of personnel and other traffic
- On occasions the nature of the lighting may also contribute to problems, e.g. flickering, stroboscopic effects and the type of light sources.