Spectrespecs

Spectrespecs were large, colourful spectacles that were given away free in an issue of The Quibbler in 1996. They were described as making their wearer look like a "demented, multicoloured owl." They make wrackspurts, invisible creatures that floats through one's ears causing their brain to go fuzzy, visible to the wizarding eye, according to Luna Lovegood.

Luna Lovegood wore a pair of Spectrespecs on the train ride to Hogwarts in 1996. Her unusual appearance was part of what lead Romilda Vane to tell Harry Potter that he ought to ignore his friends and come sit in her compartment instead. Harry refused.

Behind the scenes

 * In the film adaptation of Harry Potter and the Half-Blood Prince, Luna rescues Harry from Draco Malfoy's compartment on the Hogwarts Express using her Spectrespecs, which apparently allow her to see wrackspurts around Harry's head while he is under his Invisibility cloak, thus alerting her to his location. Nymphadora Tonks was the one who found Harry in the book.
 * It is possible that Spectrespecs are similar to muggle red/cyan anaglyph 3D glasses, as "see magic in 3D" was seen on the Quibbler (in the film).
 * In the book, it is unspecified as to what spectrespecs actually do.

Appearances

 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * The Wizarding World of Harry Potter
 * LEGO Harry Potter Years 5-7

Notes and references
Lorgnospectres