Goggles were reinforced safety glasses, often fastened to the wearer's head using a flexible strap. They could be worn to protect one's eyes when one was engaging in potentially risky practical activities, such as various kinds of engineering work or diving.
Uses
Iris Wildthyme once used goggles when she went diving on Mars. (PROSE: The Calamari-Men of Mare Cimmerium)
The Thirteenth Doctor was prone to wearing goggles when tinkering, notably when she built herself a new sonic screwdriver (TV: The Woman Who Fell to Earth) and while doing routine repairs on her TARDIS. (TV: Spyfall)
Kady Williams, the human host of the Gestalt, wore a pair of goggles as part of her standard adventuring outfit. (PROSE: Ring Theory)
Other references
By 2007, a classroom in Deffry Vale High School had a cupboard of goggles. The same room also contained a sign with white text over a blue background reading "Wear goggles" and "your eyes cannot be replaced", with an illustration of a human wearing goggles. (TV: School Reunion)
Donna Noble once mockingly referred to the Tenth Doctor's 3D glasses as his "clown goggles". (PROSE: Legends of Camelot)