Answer:
Without a bridle or a saddle across a thing I ride a-straddle. And those I ride by help of me though almost blind are made to see.
I always have to work with something in my eye. What am I?
I am the tool for inspiring many. Buy me in the store for not much more than a penny. Don't overuse me, or my usefulness will go. What am I?
I'm at the head of an elephant and at the tail of a squirrel
I shoot but never kills
No matter how little or how much you use me, you change me every month.