I have a dark green safety sheild, not the welding sheild, and I can see out of it just fine after dark... provided there are street lights.
During the daytime, so long as there is no light shining up into the helmet, the visor will appear black, and you won't be able to see in. With light shining up into the helmet, the visor will have a dark green tint towards the bottom edge, and you can sorta see my nose... if you look closely enough.