Abstract
This final report establishes the scientific validity of the ocular measure "Perclose" as a generally useful and reliable index of lapses in visual attention, i.e., the percentage of eyelid closure over the pupil. Perclose was previously specified as a relevant measure of drowsiness in several driving simulator studies. In the present research, further validation of Perclose was established among other measures, in a controlled sleep deprivation study, using a well-known psychophysical index of lapses in visual attention, i.e., Psychomotor Vigilance Task (PVT). The present study provides the scientific and practical basis to relate real-time lapses in visual attention to over-the-road driving performance. (Author/publisher)