The present invention discloses an optic system for providing illumination and imaging functions in an optical navigation system. Generally, the optic system includes a unitary optic component having an illumination lens and at least one prism to project a collimated beam of light from a light source in the optical navigation system onto a surface, and an imaging lens to image at least a portion of the illuminated surface to an array of photosensitive elements. In one embodiment, optic system further includes an aperture component having a precision aperture, the aperture component configured to locate the precision aperture between the imaging lens of the unitary optic component and the array of photosensitive elements in a path of light reflected from the portion of the illuminated surface to the array of photosensitive elements. Other embodiments are also described.