Physiological signals such as pupil size changes promise improvements for human-computer-interaction. However, the pupil response is known to be rather slow and unspecific. This hinders its application in target selection up to now. Nevertheless, there are indications for fast diameter changes accompanying cognitive processing already at early stages so that pupil effects can even precede psycho-motor activity. Building on these findings, we investigated the potential of short-latency pupil size changes for improving target selection in a search and select task. Pupil assisted target selection (PATS) was shown to be competitive to both, purely pupil-based and to dwell-time based selection modes in regard to selection times, but at the cost of more false positives than for a dwell-time approach in a search and select task. This demonstrates the usefulness of PATS as a means for target selection. The observed pupil dynamics correspond to early signal courses in basic research. Pupil dynamics also suggest room for further improvements of the integrated concept of pupil-assisted target selection.