Abstract: The pupil-measuring capability of video eye trackers can detect the task-evoked pupillary response: subtle changes in pupil size which indicate cognitive load. We performed several experiments to measure cognitive load using a remote video eye tracker, which demonstrate two extensions to current research in this area. First, we show that cognitive pupillometry can be extended from head-mounted to remote eye tracking systems. Second, we demonstrate the feasibility of a more fine-grained approach to analyzing pupil size data gathered with an eye tracker, which provides more detail about the timing and magnitude of changes in cognitive load.