a handheld optical navigation device may include a first radiation source configured to produce a first beam of radiation onto a surface below the device , a first sensor configured to receive a first image based upon reflected radiation from the surface below the device , and to identify movement of the device based upon the first image for providing a first control action , and a second sensor configured to receive a second image based upon reflected radiation from an object different from the surface below the device , and to identify movement of the object based upon the second image for providing a second control action .