Ocular parameters as an objective tool for the assessment of truck drivers fatigue

Yair Morad*, Yaniv Barkana, David Zadok, Morris Hartstein, Eran Pras, Yosefa Bar-Dayan

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Ocular parameters are influenced by sleep derivation and the use of chemical substances which are two major causes for traffic accidents. We assessed the use of these parameters as an objective screening tool for a driver's fitness for duty. Pupillary diameter, pupil reaction to light and saccadic velocity were measured in 29 army truck drivers every morning for two months and compared to baseline measurements taken while the subjects were alert. An index which expressed the difference between study and baseline measurements was calculated, and drivers with significant deviation from baseline were disqualified and interviewed. Non-disqualified drivers served as controls. Twenty-nine percent of disqualified drivers reported sleeping less than the minimum of 7 h required by army regulations compared with 8% of control drivers (p = 0.01). Disqualified drivers had worse sleep quality the night before the test (Groningen Sleep Quality Scale, p = 0.03) and incurred more accidents per driving day during their service (0.023 vs. 0.015 accidents/day, p = 0.03). Two disqualified drivers admitted to using alcohol or sleeping pills. Thus, these ocular parameters may serve as a screening tool for drivers that are at high risk for driving. Drivers who were disqualified even once, tend to be involved in more motor vehicle accidents than their peers.

Original languageEnglish
Pages (from-to)856-860
Number of pages5
JournalAccident Analysis and Prevention
Issue number4
StatePublished - Jul 2009


  • Ocular parameters
  • Sleep deprivation
  • Truck driver


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