Figure that an EMP attack from high altitude could be defended against, at critical infrastructure levels with the same sort of technology used to prevent flash

Figure that an EMP attack from high altitude could be defended against, at critical infrastructure levels with the same sort of technology used to prevent flash blindness among nuclear bomber pilots. Polarized Lead Zirconium Titanate (PLZT) goggles are able to render themselves dark before the flash of a nuclear blast can harm one's eyes. You have to figure the visible spectrum flash travels at the speed of light, along with the rest of the electromagnetic energy dumped by a particular weapon. While EMP attacks might not "flash" in the visible spectrum in the same way an atomic or thermonuclear bomb might, the principle is probably similar, in that the pulse can be detected and electronic could be rendered safe before damage could penetrate live, energized circuits.