Contact lenses: Handle with care for iris recognition

Many iris recognition systems operate under the assumption that non-cosmetic contact lenses will not affect match quality and the convenience using iris biometrics. We show results opposing this belief with a study of 51 contact lens wearing subjects and 64 non contact lens wearing subjects. Our experimental results show that contacts lens wearers are 14 times more likely to be falsely rejected by the IrisBEE iris recognition system at a Hamming distance threshold of 0.32 than non contact lens wearers. We further classify contact lens wearers into four categories according to the type of lens and its visibility in the iris image. The false reject rate varies with different types of contacts and the artifacts they produce on iris images. This is the first work that we are aware of to look at the effects of prescription contact lenses on iris biometrics.