Eyewear was a category of devices worn over a person's eyes. They can serve to either protect the eyes from the elements or to aid a person's vision.
Sun glasses were a form of eyewear worn by individuals to protect their eyes from a sun's rays. Captain Jonathan Archer wore sunglasses (as well as a hat, which also serves to protect the eyes) during his venture into the Vulcan's Forge with T'Pol. He offered his glasses to T'Pol so she, too, would have some protection from the effects of Vulcan's suns. She refused them, however, stating that her inner eyelid would suit her needs. (ENT: "The Forge")
While on a beach somewhere on Earth to meet up with Deanna Troi in 2377, Reginald Barclay wore a pair of sun glasses with an additional pair of protective lenses attached to them to give his eyes additional protection from the sun. (VOY: "Inside Man")
The VISOR was a device worn by some blind personnel, such as Geordi La Forge, to enable them to see. It allowed vision over a wider section of the EM spectrum than normal vision, but many found the extra information difficult to interpret. (TNG: "Encounter at Farpoint", Star Trek: The Next Generation, Star Trek Generations, Star Trek: First Contact, Star Trek: Insurrection, Star Trek Nemesis)