I also use one, been using it for awhile. I recalled the fogging up of the old rubber cup and the old demist shield (which barely worked) and if you take off the rubber cup or you fold it back, it leaves this tell-tale green glow in your eye socket.
So the amber filter, it changes the green to more of a filtered green. Red is the color that can cancel out green, but you don't want too much red. So they chose amber as the best compromise. It may take time to get used to, but I sort of got used to it relatively fast. Over time, it may try and come off on it's own, so be careful installing it and don't take it off unless you need to. It doesn't leave the tell-tale glow in the eye socket anymore, no need for the rubber cup, and the rubber ring takes bumps and also serves to further shade your eye when down to prevent any residual glow from escaping. Either this, the sacrificial lens or both, have to be cleaned carefully or you risk removing the coating. So heads up. But I think the .mil demist or sac. windows are the same way anyway.
Another good part to get is the removable sacrificial lenses from Wilcox. It's costly upfront, but cheaper down the road.
That part will make fitting of certain accessories impossible, such as the daytime filter. So what I use is a Butler Creek flip up cap on mine. I'm sorry, I forget which size fits and I have it put up or I'd check. Easy to determine with a string and a ruler, but you gotta get the right one. Anyway, this flip up with a very small hole drilled in the dead center, cleaned up with an Exacto-knife, will yield a great protective flip up cover/daytime filter better than the original. Doesn't interfere with the weapons mount or Wilcox sac. window either.
Off the subject, but the Crye headmount is something to look at if you don't have one. For $150, I got that and the Wilcox shroud pictured with it and I seldom use my $900 carbon fiber helmet anymore! It's that comfortable, and for a soft mount, it's not at all like a skull crusher, more like a baseball cap with with a chinstrap and NODs instead of a bill. Best way to describe how it feels, may have not bought the helmet had I known about this.
I consider all of the above essential PVS14 gear, so that's why I listed it all. Well, that and a good mount. I use the INVG, but there's other good ones by both makers, just stick with dovetail if possible.