Abstract: The invention relates to a television system which includes a broadcast data receiver for processing received data and generating television programs via a display screen and capable of generating on the screen a range of user selectable options relating to functions or modes of operation of the system. The user makes the selection of an option by using a remote control device which includes a light detection device and which can be pointed at the screen at a particular position to define a particular option to be selected. When the electron or CRT beam of the screen passes the field of vision of the light detecting device, a signal is transmitted to the broadcast data receiver and the position on the screen is determined and, with comparison to the known locations of the selectable options on the screen, the appropriate option is selected and performed.