Granted I know nothing of NVGs in particular, but the RoHS hasn't ended the world of electronics. Most manufacturers have altered their processes to RoHS-compliant materials, and unless there are parts of the NVGs that absolutely have to be made of the deadliest of materials, I'd wager my breakfast (not that hungry anyway) that they will be compliant soon (depending on your definition). Mostly 'just' a matter of choosing compliant components and using the right soldering processes and such.
I think this is one of the few not entirely bad things the EU has come up with, and if it's purely an attempt to alter competition in favor of European companies, then it's not working properly. For most types of electronics, the transition isn't that hard, and many products on the market are already compliant, and tomorrows breakfast says the majority of it is not made within the EU.