Using the Mason Lid, trace a circle out of the white foam. For the bags with two eyeballs, trace two circles.
Use your googly eyeball to trace around it onto the brown foam sheet, making a brown foam circle about the same size as the googly eye.
Cut the brown foam circle out. You may need to trim it down a bit, depending on whether it will fit your googly eye.
Flip the eyeball around and cut the back off - or mostly off.
Insert the brown foam - where the white backing used to be - Now; you have a brown eye.
Glue that onto the center of the white foam circle
Glue the white foam with the eye onto the inside of the Mason jar lid.