Why do we have peripheral vision?

Early warning: Central vision is for fine detail - reading, face recognition, etc. Peripheral vision, of low acuity, is sensitive to motion and serves to provide early warning of threats from the sides and also provides orientation to the major features of the visual space. With no peripheral vision (called tunnel vision) you cannot drive, or easily walk around, etc.

Automatic: Peripheral vision which is the perception of visual input by the outer reaches of your retina is an automatic function as long as the eyes are open. Peripheral vision is especially sensitive to moving objects which we need to prevent hazards in our life space.