first take apart a baseball at its stitching's,then get some shoe polish and rub it over the baseball.
after that get 1 Gatorade bottle cap and cut off the outside of the rubbery part of the cap,then sand it down so the paint will stick and look nice.after that step get a pair of safety glasses and sand around the looking holes so the glue will stick really well

Step 1:

so then i found some gears laying around the work table so i decided to use them.i painted them hammer copper spray paint to give it the worn copper.then i used a camera lens for the right eye piece and the bottem cover on the left lens.
with the pictures you see below should give you a good idea on how to build a pair