The effect of pupil dilation with tropicamide on vision and driving simulator performance.
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.
Potamitis
T
T
Academic Unit of Ophthalmology, Birmingham and Midland Eye Centre, UK.
Slade
S V
SV
Fitt
A W
AW
McLaughlin
J
J
Mallen
E
E
Auld
R J
RJ
Dunne
M C
MC
Murray
P I
PI
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
D009184:Mydriatics; D014331:Tropicamide