DC heroes often wear masks to protect their identities, but Green Arrow has another reason to use his - to protect his eyes from himself.
Warning: contains major spoilers for Green Arrow 80th Anniversary Spectacular #1!
Green Arrow is known for his assorted trick arrows, but his mask is also hiding a few tricks of its own. Green Arrow 80th Anniversary Spectacular #1 reveals one of the main reasons Olliver wears his mask - besides just as a standard disguise for protecting his identity. It also protects him in other ways when it comes to fights.
When it comes to equipment, Green Arrow’s had it all. Trick arrows and a cool bow are Green Arrow's main pieces of equipment. He's even had his own car and a signal in the sky like Batman's. For trick arrows, he has a boxing glove arrow, a grappling hook arrow, explosive arrows, tumbleweed arrows, handcuff arrows, and a mapping arrow - amongst numerous others. While some of these are quite silly, others are incredibly useful. Although these tend to go out of use as the arrows change, his mask is a consistent piece of equipment that he always uses.
Star City Star is a story within Green Arrow 80th Anniversary Spectacular #1, created by Phil Hester, Ande Parks, Trish Mulvihill, and Clem Robins. Green Arrow is thrown up against numerous foes and to get the upper hand on one, he looses an arrow that triggers a blinding light. If his mask were purely for protecting his identity, he'd be blinding himself just as much as his enemies. However, it isn't. His mask also has polarized lenses, which protect his eyes from his own arrows' special abilities.
Having this feature to his mask prevents him from having to wear additional gear to use flash arrows, while also protecting him from external flashes he doesn't cause. This is thanks to high-tech polarized lenses being included in the design. Naturally, he got such a great toy from Waynetech - the company that Bruce Wayne owns. After all, as Green Arrow points out, "billionaire playboy crime-fighters stick together." Batman is known for his diverse gear and equipment that allows him to be ready for action. He's had numerous Batmobiles, grappling guns, batarangs, and other assorted weaponry and tools kept in his utility belt. While he doesn't use arrows, he still makes sure that his friends can do their job as effectively as possible.
Not having powers puts Batman and Green Arrow at the same disadvantage, which means they have to strategize ahead of time much more often than heroes like Superman. They need ways to tip the scales in their favor, which means using top-notch gear to get an advantage. While their gear is different, it serves the same general purposes and some of them have the same function - such as Batman's grappling gun and Green Arrow's grappling arrow. This also reveals that these two heroes might be sharing technological developments more than was previously realized. While the Dark Knight has been known to fund the Justice League, this seems more like a mutual partnership of peers. Green Arrow has some major connections and they allow him to have the best gear. His secret identity stays safe, he can use trickier arrows that affect his foes' ability to fight, and he can be protected from external bright lights that may be directed towards him. Green Arrow's mask is truly versatile and an essential accessory.
