Recent findings demonstrate that the perception of other people's eye gaze direction can be dramatically biased by previous adaptation to that gaze direction. Here, we further investigated this aftereffect by examining its development over time, with particular attention to the potential role of the ambiguity of the test stimulus. Following adaptation to gaze to one direction, participants' ability to correctly classify gaze to the adapted direction was severely impaired, both for ambiguous and relatively unambiguous test stimuli. Of particular importance, this aftereffect decreased over time but remained measurable up to 7 minutes post adaptation, with its decline following an exponential decay function. The implications of the present findings are discussed with respect to both coding mechanisms involved in gaze perception and a potential role of adaptation effects in real life situations.