1. A head-worn computer with an eye-imaging system, comprising: a camera system positioned in a head-worn computer, wherein the camera system is further positioned to capture eye-image light that originates as reflections from an eye of a user, wherein the camera system is further positioned to capture the eye-image light as a reflection from a partially reflective surface that is positioned in front of an image display in the head-worn computer, wherein image light, from the image display, is transmitted through the partially reflective surface; and a processor adapted to detect when the head-worn computer is mounted on a user's head, wherein the processor is further adapted to cause the camera system to capture the eye-image light after the processor identifies that the head-worn computer has been mounted on the user's head, and wherein the processor is further adapted to cause a comparison of the captured eye-image light with a pre-stored eye image of a known user of the head-worn computer, and wherein, in the event the comparison confirms the identity of the known user, the user is granted permission to view content to be presented in a display of the head-worn computer.