| abstract |
(57) Abstract: An optical element including a substrate provided with a transparent coating (9) containing a photochromic material, wherein the transmittance of the optical element changes according to a change in light in a visible region. This optical element is characterized in that the coating (9) contains an inorganic network of silicon oxide and an organic polymer which is chemically bonded to the inorganic network via Si-C bonds. Preferably, macroscopic particles of a metal oxide are incorporated in the network, and the metal is preferably selected from the group consisting of Al, Si, Ti, Zr, In and Sn. Preferably, a metal oxide having a size of 5 nm or more is used. Such a photochromic coating (9) has scratch resistance and exhibits good switching behavior. This coating can be used, for example, for the display window of the display device (1) and for sunglasses. Also disclosed is a method of making the layer. |