Automatic quantification of pupil dilation under stress

Response of the autonomic nervous system can be assessed by quantifying the dilation of the pupil of a human placed in darkness. When the intensity of the surrounding light is low, human's pupil dilates to capture a maximum number of photons. This type of dilation is known as dark adaptation. The aim of this study is to test the hypothesis that dark adaptation is slowed proportional to the amount of stress that an individual has experienced. We have developed a new tool for automatic quantification of pupil dilation. Our system uses statistics of the color of the pupil and the iris as well as model-to-image registration and region growing segmentation techniques. Our system has been tested on several images and shows high correlation with hand segmentation.