Abstract
Recent studies on photochromism in organized media such as crystals, liquid crystals, Langmuir-Blodgett films and bilayer membranes were described, The main topics are as follows :
1) Photochromism in polymorphic crystals
2) Hydrogen bonding control of photochromism in the solid state
3) Photochromism in liquid crystals
4) The search for liquid crystalline photochromic spiropyrans and its success
5) Behavior of photochromic compounds in LB-films and bilayer membranes