This paper describes two studies in which two nightvision enhancement systems were examined to compare nighttime driver performance in pedestrian detection. In the first study, the levels of clutter in the images displayed by the two types of night-vision enhancement systems were measured objectively and subjectively. The subjective ratings of clutter changed as a power function of the objective measure of clutter intensity. In the second study, the effect of clutter on glance behavior during pedestrian detection was examined in a driving simulator. Night-vision images with less clutter required shorter search times and fewer glances to detect the pedestrian, but the duration of each glance remained relatively constant.