Activity
Visual field (1), preferred visual field (2) and optimum field of vision (3) of a person standing and sitting for vertical visual tasks.
Preferred field of vision for horizontal visual tasks. Preferred angle of view 25°.
The value of any particular information relates to the current activity of the observer. This activity may be work or movement-related or any other activity for which visual information is required. Lighting conditions under which the visual task can be perceived to an optimum degree can be determined from the above-mentioned specific features. It is possible to define ways of lighting which will be ideal for specific activities.