Never really thought about it until now but it makes sense to not wear them outside, especially if it is sunny. The lenses are darker which open the pupil and if there is no UV protection that could cause damage to your eyes over a period of time. Main reason to never buy cheap sunglasses.
Now how will we be told to put on our 3d glasses, I mean battle glasses, I mean night vision goggles, I mean quiditch goggles, I mean safety glasses, I mean insect eye repelant...oh heck what will these mystery tech goggles be called in the 1930's?
I do wonder how many glasses will be lost over the side of the truck outside if we are instructed to not put them on initially?
I bet the 3d will be used to cause depth to the video much like Gringotts and not so much in your face 3d. Wish this could be done without glasses!