Logic Specs Case
Invented in the 1990s, the Logic Specs case is an unusual container for a pair of spectacles! The case is held closed by magnets. But when you open the case, you can continue to open it until each half has performed a complete revolution, and the band on the outside of the case is now a different colour! I remember a Jacob's Ladder toy purse as a child that had a similar mechanism. Very elegant and very unusual.
The Logic Specs Case comes in various colours and shapes. One changes from Red to Yellow; the other changes from Green to Purple.