1. One or more non-transitory processor-readable media having embedded code therein for programming a processor to perform a method of detecting a potential defect in an image, the method comprising: storing a first value indicative of a position of a source of light relative to a lens; wherein the first value indicates whether the source of light is: to the right of the lens, to the left of the lens, to the bottom of the lens, to the top of the lens, to the top right of the lens, to the top left of the lens, to the bottom left of the lens, or to the bottom right of the lens; determining a second value indicative of a distance between an image capture apparatus and a subject; determining a third value indicative of a lens focal length; determining an in-image pupil size based, at least in part, on the first value, the second value, and the third value; using the first value to identify an expected orientation for a half-red eye defect; and identifying defect candidates in the image at least in part based on the expected orientation and the in-image pupil size.