It's a bird! It's a plane! No wait, I can't really tell, Then I must be me, only three letters to spell

Close one eye? Not so fast! No need to wink with this spyglass. Gaze at stars. Read far off words. One common use is for the birds!

A eight letter word for a bag with shoulder straps, carried on the bag, typically made of canvas. The first four letters can mean shape by striking as with flint. The last four letters can mean a large bag sometimes made of burlap.