Gnomish Power Goggles are crafted by Engineers with a skill level of 375 who also have the Gnomish specialty. As they bind on pickup, the only way to get a pair of these goggles is to be a Gnomish Engineer and make them yourself. The schematic can be learned from Gnomish Engineering trainers (Tinkmaster Overspark in Ironforge for Alliance or the neutral Oglethorpe Obnoticus in Booty Bay if you're Horde). You cannot learn this schematic unless you have specialized in Gnome Engineering.