For what's worth, the gorgon and the basilisk represent different theories of vision in their different abilities to petrify. A basilisk petrifies its victim by seeing the victim; a gorgon petrifies her victim by being seen by the victim. Ancient people variously imagined vision as active, as passive, or as a combination of active and passive. Petrification comes actively from the eyes of the basilisk; not so, or at least not simply so, in the case of the gorgon.