An optical computer mouse has a support structure that can be moved across a surface. An illumination source that illuminates a region of the surface is coupled to the support structure. An imaging system in the mouse includes an optical sensor array that receives light from the illuminated region of the work surface and an image processor that receives data from the optical sensor array. The optical computer mouse may be switched between a navigation mode of operation, in which the image processor detects motion of the optical computer mouse over the work surface, and a barcode reading mode of operation, in which the image processor senses a barcode as the optical computer mouse is moved across a barcode.