Try this activity to see why we have two eyes rather than just one. You will need a cup, some buttons and a friend.
1) Sit at a table with your friend and put the cup between you.
2) Cover one eye. Ask your friend to hold a button and move it about over the table. When you think the button is over the cup ask your friend to drop the button into the cup. How many times out of five did you get it right?
3) Now repeat the experiment, but this time use both eyes. Is your score
better when you use both eyes?
When you use only one eye to see, you cannot tell exactly where your friend's hand is. When you use two eyes you can judge depth and distances better.
