Mirrors in art from Van Eyck's Arnolfini Portrait to Velazquez, Manet and Escher: what each painted mirror shows and what the optics predict.

Colour music from Castel's ocular harpsichord (1725) to Rimington, Scriabin and Wilfred - and what Brewster wrote about the kaleidoscope in 1819.

What makes a kaleidoscope handmade, how to judge optical quality and materials by eye, and why a brass instrument on a desk counts as functional art.

How to choose executive desk accessories that stay on the desk: four tests, three desk zones, common categories and where a brass kaleidoscope fits.

Kaleidoscopes, teleidoscopes, prisms and mirror constructions: what makes an object optical art, what to check, and where to buy from makers.