MotionVision.

Peripheral vision helps you sense motion from the side. But can you actually see what's moving? Try this!

YOU NEED:

a friend * chair

TO DO:

1. Have a friend sit on the chair and look straight ahead. Stand behind your friend's chair.

2. Place your hands shoulder-width apart behind your friend's head. Hold up a random number of fingers on each hand, then slowly move both hands forward.

3. Have your friend call "left" or "right" as soon as he or she sees your hand out of the corner of an eye. Stop moving your hands. Can your friend see both hands?

4. Keeping your hands in place, ask your friend: How many fingers am I holding up? Did he or she get the right number?

5. Continue moving your hands forward until your friend can call out the correct number of fingers on each hand.

CONCLUSIONS: How wide is your friend's field of vision? Can he or she see objects clearly in the entire field of vision? Why or why not?