title: The effect of pupil dilation with tropicamide on vision and driving simulator performance.
abstract: OBJECTIVE
  To assess the effect of pupil dilation on vision and driving ability.
  
  
  METHODS
  A series of tests on various parameters of visual function and driving simulator performance were performed on 12 healthy drivers, before and after pupil dilation using guttae tropicamide 1%. A driving simulator (Transport Research Laboratory) was used to measure reaction time (RT), speed maintenance and steering accuracy. Tests of basic visual function included high- and low-contrast visual acuity (HCVA and LCVA), Pelli-Robson contrast threshold (CT) and Goldmann perimetry (FIELDS). Useful Field of View (UFOV--a test of visual attention) was also undertaken. The mean differences in the pre- and post-dilatation measurements were tested for statistical significance at the 95% level using one-tail paired t-tests.
  
  
  RESULTS
  Pupillary dilation resulted in a statistically significant deterioration in CT and HCVA only. Five of 12 drivers also exhibited deterioration in LCVA, CT and RT. Little evidence emerged for deterioration in FIELDS and UFOV. Also, 7 of 12 drivers appeared to adjust their driving behaviour by reducing their speed on the driving simulator, leading to improved steering accuracy.
  
  
  CONCLUSIONS
  Pupillary dilation may lead to a decrease in vision and daylight driving performance in young people. A larger study, including a broader spectrum of subjects, is warranted before guidelines can be recommended.
authors.affiliation: Academic Unit of Ophthalmology, Birmingham and Midland Eye Centre, UK.
authors.forename: T
authors.initials: T
authors.lastname: Potamitis
authors.forename: S V
authors.initials: SV
authors.lastname: Slade
authors.forename: A W
authors.initials: AW
authors.lastname: Fitt
authors.forename: J
authors.initials: J
authors.lastname: McLaughlin
authors.forename: E
authors.initials: E
authors.lastname: Mallen
authors.forename: R J
authors.initials: RJ
authors.lastname: Auld
authors.forename: M C
authors.initials: MC
authors.lastname: Dunne
authors.forename: P I
authors.initials: PI
authors.lastname: Murray
mesh_terms: D000328:Adult; D001334:Automobile Driving; D015350:Contrast Sensitivity / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000009:adverse effects*; D014331:Tropicamide / Q000009:adverse effects*; D014786:Vision Disorders / Q000139:chemically induced*; D014787:Vision Tests / Q000379:methods; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D009184:Mydriatics; D014331:Tropicamide