Of all the inventions derived from early optical research, one of the best loved and most enduring is the kaleidoscope. Patented in 1817 by Sir David Brewster, the kaleidoscope became an instant success and remains to this day a popular gadget among young and old.

While conducting experiments on polarity in the early nineteenth century, Brewster noted that two mirrors set at thirty degree angles would create a near-infinite reflection image. He placed his mirrors in a tube with brightly colored beads in the base, and the kaleidoscope was born. Brewster's invention was immensely popular and was also easy to pirate; consequently, Brewster earned almost nothing from its sales.

Since its conception, the kaleidoscope has undergone remarkably few modifications. Polarized planes and colored foils have often replaced Brewster's beads, but the essential design is unchanged. In addition to timeless amusement, the beautiful images seen through the kaleidoscope's peephole have served as inspiration for new carpet, wallpaper, and fabric designs.