Okay, having translated the bit about lasers being fast to lasers be low power (it took a minute), I am confident in saying this:
I don't know a whole lot about lasers, but having a laser above 5mW is certainly not illegal. There's a 50 mW laser about 25 feet from me as the crow flies, and you can get a 1 watt laser Now, those are both frankly dangerous, but a 5mW laser straight to the eye is going to cause damage in more time than it takes to blink. To risk eye damage, you'd have to not blink when a bright light suddenly hit your eye. You'd have to have direct contact, laser straight to your eye, for more than that blink took. Why take the risk? I can't speak for the arenas in question, but I'd say there's more risk falling and getting a concussion on a doorway playing airsoft than taking laser damage in the eye.
Shall we pad the door edges?