There is provided a system for modulating user commands via command input images displayed on a graphical user interface based on a user viewing direction relative to the displayed command input images and the graphical user interface. The system uses an image capturing device for capturing real time images of a user's face, eyes and irises and determines the eye orientation. The system separates the graphical user interface into interface portions and determines a correlation between the eye orientation and one or more portions to determine if any of the foregoing are viewed portions. The system determines whether a viewed portion contains a command input image and only allows user input commands via the command input image to be processed if the image is within a viewed portion. The system can modulate a position of a command input image displayed on a graphical user interface and movable thereon based on a user viewing direction relative to graphical user interface thereby moving an input image from a first position to a second position that corresponds to a viewed interface portion. The system provides for simultaneously displaying multiple graphical user interfaces via the same display, whether the multiple graphical user interfaces are hosted by one or more remote host controllers.