Genetically identical irises have texture similarity that is not detected by iris biometrics

As the standard iris biometric algorithm “sees” them, the left and right irises of the same person are as different as irises of unrelated people. Similarly, in terms of iris biometric matching, the eyes of identical twins are as different as irises of unrelated people. The left and right eyes of an individual or the eyes of identical twins are examples of genetically identical irises. In experiments with human observers viewing pairs of iris images acquired using an iris biometric system, we have found that there is recognizable similarity in the left and right irises of an individual and in the irises of identical twins. This result suggests that iris texture analysis different from that performed in the standard iris biometric algorithm may be able to answer questions that iris biometrics cannot answer.

► We present the largest experiment to date comparing irises of identical twins.
► We verify that biometric software sees no similarity between left and right irises.
► We pioneer research in human perception of genetically identical iris similarity.
► We compare human performance on whole-eyes, irises, and periocular images.
► We show evidence that humans can learn to judge genetic relatedness of eye images.