anamorphoscope
noun/ænəˈmɔːfəskəʊp/
Etymology From anamorphosis + -scope.
1
A mirrored device which gives a correct image of an anamorphosis.
- The classical anamorphoscopes, he went on to explain, were mirrors, cylindrical or conical, usually, which when placed on or otherwise near a deliberately distorted picture, and viewed from the appropriate direction, would make the image appear “normal” again.2006, Thomas Pynchon, Against the Day, Vintage, published 2007, page 280: