1. An apparatus for authenticating a subject, comprising: an image projection device to generate and project an image of a pattern onto at least a part of a cornea of an eye of the subject, wherein the image projection device includes at least one light ring is configured to generate and project at least one ring in the image of the pattern; an image capture device to capture an image of the pattern after reflection in at least a part of the cornea of the eye; and a computer processor to determine one or more data sets defining locations of discrete points that each correspond to at least part of the reflected pattern in the captured image, wherein the computer processor further compares at least one of the one or more data sets with a reference set, the reference set being based on a previously captured image of the pattern after reflection from at least part of the cornea of the eye of the subject, and outputs an indication of whether the subject is authenticated or not.