The term 'Light Controller' refers to a device or system that is used to control the intensity of light. The two crossword solutions for this term are 'IRIS' (4 letters) and 'DIMMER' (6 letters). An IRIS is a device that is used to control the amount of light entering a lens, while a DIMMER is a device that is used to adjust the brightness of an electric light. Both of these devices are used to control the intensity of light in different ways.