Some substances have two different light bending powers (indexes of refraction) that depend on the polarization of the light entering the substance. These substances, usually crystals, are called BIREFRINGENT. Calcite (Icelandic Spar variety) is one such material. When placed over a typed word on a page, you will observe two words, one for each polarization, through the crystal.

Area Sign - Bending Light
Pinball Machine
Polarized Image Mosaic
Polarized Light Island
Polaroid Island (Audry's)
Rotating Light

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