Teashades, also known as “John Lenon glasses” or “Ozzy Glasses” are wire-rim sunglasses with circular lenses which are largely associated with John Lenon, and more recently Ozzy Osbourne.
Teashades originally became popular during the 1960’s, especially among hippies and other counter-culture groups at the time, and were often decorated with psychedelic colors. Modern teashades tend to be more reserved in terms of color, but still have a bit of the funky, counter-culture connotations of the original glasses.
Teashades are still very much outside the mainstream when it comes to sunglasses, but you may be able to pull them off if you are going for a vintage/hipster look. The associations with the Sixties also make teashades a good choice for hippies, and it’s popularity among popular rock stars makes it a good fit for musicians as well.