A photochromic light control mirror comprises a photochromic substrate having a reflective film deposited at one side thereof. Alternatively, a mirror (i.e., a layer of glass having a reflective film deposited at one side thereof) is coated with a photochromic coating. An ultraviolet light source illuminates...http://www.google.com.au/patents/US5373392?utm_source=gb-gplus-sharePatent US5373392 - Photochromic light control mirror
