Your vision is divided into central vision and peripheral vision. The main functions of the peripheral vision are:

recognizing movement and changes in light conditions

taking in your surroundings

alerting your brain to things your central vision should focus on (the warning reflex)

Your entire field of vision spans approximately 180 degrees. Peripheral vision accounts for most of this field, with the exception of the area your central vision spans (3-5 degrees in the centre). Your entire field of vision spans approximately 180 degrees. Peripheral vision accounts for most of this field, with the exception of the area your central vision spans (3-5 degrees in the centre).