No one is even 100% sure on what they do in the first place. The goggle and armguard descriptions are vague at best when we still have little idea on how the game mechanics work.
Naiya | Mithra | Windurst | Rank 10 | 1st Lieutenant | Ragnarok
WAR: 75 MNK: 75 SAM: 66
RotZ: O | CoP: O | ToAU: O | Apoch Nigh: O
Naiyah | B.Elf | 85 Rogue | Stormscale
Doubleday | B.Elf | 85 Paladin | Stormscale