[singpilot]

I have been going in and out of Las Vegas for years. In the early days of the Luxor Hotel, there were lasers aimed indescriminately up from the building as part of the light show that emanates from there. On departure (climbing out of McCarren, just south of the hotel), the lasers would sometimes sweep past the cockpit. They were pretty bright, and would light up the inside of the cockpit pretty well. About the same as a lightning flash. I never happened to be looking at the source, and your natural inclination is not to do that, so I cannot say that any blindness, transient, temporary or otherwise would result. It was more of a startle kind of thing. The hotel modified the computer that aimed the lasers to avoid any shining anywhere towards the flight path. In fact, I think they have since been removed.

I suspect that even if one was intentionally aimed at a cockpit, it would have to be pretty strong, and happen to actually catch BOTH pilots looking at the source to have a chance of downing an airplane.

Now I know that certain agencies in the Govt. think that there is a plan to use them for terror, but I think it would have to have a fair amount of luck to succeed.

YMMV.