The eyes are more than windows to the soul, thanks to technologies that can reveal reflected faces in pupils of photographs. Dr. Rob Jenkins of the University of York's Department of Psychology published a study that showed how pupils in photographs of faces can be "mined" for hidden information.

The study simulated crime photos, in which victims are photographed by attackers, to examine the reflections in the eyes of those being photographed. Jenkins and co-researcher Christie Kerr of the University of Glasgow's School of Psychology photographed eight people who were looking at four other individuals behind the camera. By zooming in on the high-resolution photos, Jenkins and Kerr were able to recover bystander images that were then accurately identified by the eight individuals photographed, even if the image quality was poor.

Despite poor image quality, face reflections were accurately identified

Crime investigators often use photographic evidence to try to catch perpetrators. Face photographs could now provide investigators with more information to catch criminals, not only in the form of facial recognition, but also because pupils can reflect the appearance of the surrounding area. This could help investigators piece together an individual's location as well as the network of people involved in a crime.

There are some limitations to the forensic use of photographs like these. Jenkins shot his study photographs with a 39-megapixel Hasselblad camera, and the subjects must be looking straight into the camera when the photo is shot for the best results. No one can control the circumstances in which a crime photo is shot, but the research does show a new tactic investigators have at their disposal.