  Iris recognition systems, operating in the near infrared spectrum (NIR), have
demonstrated vulnerability to presentation attacks, where an adversary uses
artifacts such as cosmetic contact lenses, artificial eyes or printed iris
images in order to circumvent the system. At the same time, a number of
effective presentation attack detection (PAD) methods have been developed.
These methods have demonstrated success in detecting artificial eyes (e.g.,
fake Van Dyke eyes) as presentation attacks. In this work, we seek to alter the
optical characteristics of artificial eyes by affixing Vanadium Dioxide (VO2)
films on their surface in various spatial configurations. VO2 films can be used
to selectively transmit NIR light and can, therefore, be used to regulate the
amount of NIR light from the object that is captured by the iris sensor. We
study the impact of such images produced by the sensor on two state-of-the-art
iris PA detection methods. We observe that the addition of VO2 films on the
surface of artificial eyes can cause the PA detection methods to misclassify
them as bonafide eyes in some cases. This represents a vulnerability that must
be systematically analyzed and effectively addressed.
