A sun visor was a piece of headgear which could conceal someone's eyes from sunlight, as well as from other people.
In preparation for an assassination attempt to be made on Wedge Antilles after he officially resigned his commission in the Five Worlds military, his wife prepared a package, including a sun visor, for Antilles to be able to get away unnoticed. The arms dealer "Gundark" sometimes wore a sun visor.
- Gundark's Fantastic Technology: Personal Gear