This is a funny topic, isn’t it? It sounds ridiculous and guess why. Because it is!
First of all, such thing as “laser party” does not exist. Or does it? So what is it then?
I know about laser displays as such, I know about laser display systems that are used for laser shows and I heard about Clubmax laser system manufacturer which is Slovakian company called Kvant. But I’ve never heard about an event that would be called “laser party”.
And because of that, it is impossible to say, what dress you should wear if you go to a laser party, because you can’t really go to something that doesn’t exist 😀
If you go to a party where some laser beams are bouncing around you, ask the party organiser to show you a proof that the laser display was signed off by someone from local authority and that it can be considered to be safe for you and your mates to watch. What dress you wear during this is not that important at all.