David Brewster's Prism

Origin
Sir David Brewster was a Scottish physicist, mathematician, astronomer, inventor, writer, historian of science and university principal.

Most noted for his contributions to the field of optics, he studied the double refraction by compression and discovered the photoelastic effect, which gave birth to the field of optical mineralogy. For his work, William Whewell dubbed him the "Father of modern experimental optics" and "the Johannes Kepler of Optics."

He is well-recognized for being the inventor of the kaleidoscope and an improved version of the stereoscope applied to photography. He called it the "lenticular stereoscope", which was the first portable, 3D viewing device. He also invented the binocular camera, two types of polarimeters, the polyzonal lens and the lighthouse illuminator.

Effects
When held up to light, the prism creates a static copy of the holder. The copy is intangible and will vanish when contact is made with it. Once the illusion vanishes, the users vision will become kaleidoscopic for a few seconds before returning to normal.