Well, i think they word "blinded" was overstated, but could be more accurately compared to the "blinded" you might say when someone has their high-beam lights on as you are driving down the highways and it is hard to see. For starters, the plane was at least 10,000 feet if they are 40 km from airport (that is 3,048m or 3 km). if you take any of those green pen lasers and hold it against your skin for an hour it won't burn it. Now, as the focused point of light gets further away the dot grows in size (lasers are great for keeping the light beam together, but it still spreads). So if the plane was at least 3km directly above you, it wouldn't shoot through the floor. But if it was say 45 degrees above and away, that would be 5 km. (remember, the article said it was 40 km from airport, so it wasn't skimming the roof tops - it would be holding at 3km vertical). So, at 5 kms, the pen laser dot would be huge (diluted). Have a look at this physics article https://www.physics.utoronto.ca/~jharlow/teaching/lasers.htm...
