I like one letter but I?m written with three-Riddle

Riddle 
Gogo and Dhamaka Singh get into a fight over the answer of this riddle! Let's see if you can figure it out. I sound like one letter but I'm written with three. I show you things when you look through me. What am I?

    Eye!

Mindyourlogic Riddle: Answer:
I like one letter but I?? written with three-Riddle