1. A vehicle comprising: a compartment; a crash sensor system arranged to detect a crash involving the vehicle; a restraint system having a variable actuation in the event of a crash involving the vehicle; an occupant monitoring system for obtaining information about occupancy of said compartment and controlling said restraint system based on the obtained information, said occupant monitoring system comprising: at least first and second optical imagers for obtaining images of a common area of said compartment, said first and second imagers being spaced apart from one another; and processing circuitry coupled to said crash sensor system, said restraint system and said first and second imagers and arranged to derive information from images obtained by said first and second imagers and control the actuation of said restraint system based on the derived information and on detection of a crash by said crash sensor system, said processing circuitry being arranged to identify the occupant such that the presence of different types of occupants is determinable and said restraint system is controllable to provide different actuations depending on the type of the occupant.