[Visual field and road traffic. How does peripheral vision function?].

Peripheral vision is very important for visual perception in all fields of traffic. The central visual field is most important because the major part of information input occurs here. The peripheral parts of the visual field have excellent motion detection and the capability to perceive flicker stimuli. In addition to the central visual field the horizontal parts to the left and right are important, especially for road traffic. Information input occurs in a continuous sequence of saccadic eye movements which transport critical objects into the fovea. After fixation, the observer analyses the object and decides whether or not a reaction is necessary. Triggering of a saccadic eye movement only can occur if the critical object is suprathreshold in size, contrast, colour, motion and temporal modulation. This is the reason why perception of peripheral objects needs more time than the perception of objects in the fovea. Without an intact central and peripheral visual field participation in traffic is not possible.