The rib pinner auger got stuck in the rib while turning a corner. The wrench was put on the rib pinner auger to spin the auger out, when the wrench came out of the chuck and struck the employee in the right eye, resulting in 5 stitches and a fractured orbital bone. Compliance with rules/regs, PPE, mining equip/systems not a factor. Miner proficiency may be a factor.