Him and his friends conspired to inebriate him,causing him to fall asleep. It is then that Odysseus stabs him in the eye with a wooden stake,causing him to go blind. The next morning,as the sheep are let out to graze, Polyphemus touches their backs to ensure that his captives haven't escaped. But they were cunning, tying themselves to the bellies of the sheep and in that way managing to escape.
