Board Thread:Episode Discussion/@comment-410526-20161022144159/@comment-28288412-20161023115805

It's possible that in order to petrify the grimm the Silver Eye pierced and scarred Cinder. As the power stolen by the Grimm corresponded to and manifested in her left eye (IIRC), it would make sense if that was where the Grimm resided and thus the only part affected.