Astronomy lasers
As a poster said before, laser star-finders are very useful pieces of kit especially if the object to be identified is obscured by cloud. Ive been watching Mars in the southern sky for a few weeks but it does trouble me that my line of sight is perpendicular to a flight path. I use a red laser but it is quite astonishing how far the beam remains coherent in clear air. I am sure that astronomy lasers cannot be a more than a momentary distraction for aircrew even if it illuminates directly into the cockpit. I dont know much about "green" lasers but I would imagine that the thermal energy dissipates at short distances from the exit port of the laser. Spectacle lenses could refocus the beam however.
I would be horrified if I inadvertently endangered aircrew but would be equally horrified if I had Mr Plod and his friends descend upon me whilst I was looking at a planet.
More info is needed... which lasers are safe and which ones arent? I will do a bit of searching myself but if someone knows more then i would be grateful.