Crystallized Wisdom (叡智の結晶, Eichi no Kesshō?, lit. "Crystallization of Wisdom") is a crystallized form of wisdom gained by eating the heart of a dragon.[1] In Sigurd's case, this "crystallization" takes the form of a pair of eyeglasses.
A magical item that originally shouldn't exist in mythology. If another individual uses it, due to the enormous amount of information, a severe headache will occur.[1]