A kaleidoscope is an optical device used for the illustration of the image-forming properties of inclined mirrors that have been combined. It is an important tool for pattern designers and is commercially available as a toy.
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A kaleidoscope is basically a tube-shaped optical instrument that when rotated produces a succession of symmetrical designs by means of mirrors reflecting the constantly changing patterns made by bits of coloured glass at one end of the tube. The term may also be used to refer to a series of changing phases or events.