Put together a 10kw CO2 or N2 Gas laser, use large (shotgun shell sized) capacitors for the energy source and a diffusing lens for expanded coverage.
It can be done I once did a science project on the feasability of hand held lasers. They won't kill, but they certainly can blind.
Neither of these will reach the retina...Doubled Nd:YAG 1064->532nm is near the peak of human vision and will dazzle if not destroy the retina....