Board Thread:Speculation House/@comment-27404492-20170918133425/@comment-4010415-20170926201508

RedBlaze025 wrote: but if where going by the Grimm parasite story my theory is the silver eye power is a magical light that counters the Grimm since their stated to be "creatures of darkness". There's also the fact that Qrow said "You see, the creatures of Grimm, the most fearsome monsters mankind had ever encountered, were afraid of those silver-eyed warriors. They were the best of the best. It was said that even a single look from one of these fighters could strike a Grimm down."

A single "look" from a SEW could "strike a Grimm down." Ruby had light come from her eyes, and that's what petrified the Dragon and injured Cinder.