I use a Rigol DL3021 electronic load to test my drivers, but I'm also an electrical engineer so I use it for much more, and $500 may be a bit too much for a hobbyist. Alternatively, you could get a super cheap test load from amazon for about $30 but obviously the accuracy isn't as good though it...
If I had glasses that were rated for 400nm would they also protect somewhat against 405nm? I guess my question is how many nm +- is the rating for glasses of something like eagles?