Did Roman cavalry wear face-masks in battle?

[Nathan Ross]

At the risk of bringing up a vexing topic, there's also the question of clibanarii equipment. There are several descriptions of them wearing masked helmets, apparently as their usual kit, therefore presumably in battle. These masks probably didn't look much the CG version, and clibanarii may have been trained to ride in very tight formation (one panegyric seems to suggest something like a 'steamroller' effect was intended!), but this at least suggests that riding a horse into battle while wearing a mask wasn't completely foolish...