I was checking out the novelization of Infinite Crisis, which is I guess for people who like superheroes but hate looking at them. I would like to offer this passage, which has Superman meeting up with Batman:
A solitary figure waited for him on an elevated walkway at the centre of the ravaged nerve centre. A stark black cloak and cowl were draped over the man's equally black body armour, so that he blended in with the shadows thrown by the faint blue light. Opaque white lenses concealed his eyes.
So, the stand out line here is opaque white lenses concealed his eyes. My thought when reading it was really? Has that been decided, then? The eyes of Batman have always been a subject of debate. There are basically two schools of thought:
1. He wears a mask with white, opaque lenses to conceal and protect his eyes.
2. He wears a mask that does not have lenses, because that would obstruct his vision. His eyes are just whited out in comics for aesthetic reasons.
For the most part, Batman's eyes are white when he wears the cowl. But the same goes for, like, a million billion other superheroes. I doubt Green Arrow has lenses in that little mask. It just looks cool when the eyes are whited out, and it's easier to draw.
In all Batman movies, and in some comics, the eyes are visible (Lee Bermejo and Alex Ross both show the eyes in their art, for example). Batman Begins had some grease paint around the eyes, which I think would be a lot of effort for our hero. They were careful in that movie to never show Batman with the cowl pulled off because the paint around the eyes would look silly.
There is another possibility: retractable lenses. Batman The Animated Series had him changing his lenses to red sometimes so he wouldn't be blinded by his own flash bombs. So maybe the white lenses are also retractable.