Geneva Convention Prohibitions on Certain Weapons
Protocol IV on Blinding Laser Weapons prohibits the use of laser weapons specifically designed, as their sole combat function or as one of their combat functions, to cause permanent blindness to unenhanced vision, that is to the naked eye or to the eye with corrective eyesight devices. The High Contracting Parties shall not transfer such weapons to any State or non-State entity.
Source: United Nations
I suppose if the laser is intended to kill, then it might be interpreted as conforming to the Geneva Conventions. Maybe. I dunno man.