Final answer:
Jugglers use peripheral vision, which allows them to keep track of all the balls and their surroundings without directly looking at them. Tunnel vision, which only perceives the central visual field, is not beneficial for juggling. The answer to the question is 'a) Peripheral'.
Step-by-step explanation:
Jugglers use peripheral vision to keep track of the whole area rather than focusing on any one particular ball. This type of vision allows them to be aware of their surroundings and catch glimpses of all the balls without directly looking at them. Using peripheral vision helps them maintain a sense of the space they are working in and the motion of the balls, which is essential for successful juggling.
Contrast this with tunnel vision, where only the central visual field is perceived, which is not desirable for jugglers who need a broad awareness of their surroundings to keep all the balls in the air. Therefore, the correct answer to the question is 'a) Peripheral'.