Because it was a blunt needle, more akin to a knitting needle, and he didn't puncture his eye with it, but inserted it into the socket, between his eye and the

Because it was a blunt needle, more akin to a knitting needle, and he didn't puncture his eye with it, but inserted it into the socket, between his eye and the bone of his skull, so that he could get it as far back as he could, and deform the back part of his eye.