Answer:
What body part is pronounced as one letter, but written with three, only two different letters are used?
I am all around, yet to me you are half blind. Sunlight makes me invisible and difficult to find. What am I?
By myself, I'm practically nothing. Worthless as a leader, but when I follow a group, their strength increases tenfold. What am I?
I go up and down at the same time. Up towards to sky and down towards the ground
I am enjoyed with a pot and some pointy sticks.
As round as an apple. As deep as a cup. All the king's horses can't pull it up.