A device and method is provided for controlling a electronic device that includes a display device arranged on a first side of the electronic device, and a first optical device configured to capture optical data. An object is placed over the first optical device so as to at least partially block ambient light from the first optical device, and based on data captured by the first optical device, an input to the electronic device is assigned to the detected object. The assigned input is equated to a predetermined function of the electronic device.