For reduced power wastage, a transmissive display (100), comprises a backlight (106) and a valve (110) for modulating light from the backlight to create an image, and furthermore the transmissive display comprises: a connector (198) for connection with a connected viewer behavior detection means ((150, 152, 165), 160), and a power optimizer (120), having an input connection (C_i) to the viewer behavior detection means for receiving from it a behavior measuring signal (I_usr), and having an output (O_BL) for sending an optimal drive value (D_Lb) to the backlight (106) depending on the behavior measuring signal (I_usr).