Lasers
While the crystalline Neodymium Yttrium Aluminium Garnet laser can produce a very powerful puls of energy, it is not in the visible spectrum. Although it can penetrate the eye and burn the retna the damage is perminant (blind spots and an eye full of blood).
The green light is blinding and if the power density is kept low enough it is temporary. A few milliwats can also burn the retina.