A monitor display unit mounted on a surface and in electronic communication with a system or device to be monitored, comprising a face plate, a back plate having at least a portion of a side edge being translucent or transparent, a logic controller, and at least one light-emitting device in electronic communication with the controller. Actuation of the light-emitting device causes light to pass through the side edge of the back plate, thereby being visible to a viewer at an angle that can be generally parallel to the surface on which the display unit is mounted.