Abstract
Purpose :
Night-time driving difficulties are commonly reported by older drivers yet have not been widely investigated. This study assessed the night-time driving performance of older drivers and explored the associations between night driving ability and photopic, mesopic and glare-based vision tests.
Methods :
Participants included 26 older licensed drivers (71.8 ± 6.3 years), with a range of self-reported night driving difficulties, as assessed by the Vision and Night Driving Questionnaire (VND-Q). Night-time driving performance was assessed on a closed-road driving circuit, which included both low luminance and intermittent glare conditions. Measures of driving performance included recognition of road signs, road-side pedestrians and animals, white and black road markings and avoidance of low contrast hazards; a composite driving performance score was calculated. Vision assessment included photopic (high and low contrast) and mesopic (high contrast) measures of visual acuity (VA) and Pelli-Robson contrast sensitivity (CS). Tests of glare (Berkeley Glare Test and Aston Halometer) and mesopic motion sensitivity were also assessed. The associations between these vision measures and night driving performance were explored using regression analysis.
Results :
The composite night driving performance score was more strongly associated with mesopic visual function, particularly motion sensitivity (p=0.002) and mesopic high contrast VA (p=0.002), rather than the photopic or glare based tests. Driving performance was also reduced for participants reporting greater night driving difficulties with the VND-Q (p=0.005). The presence of glare caused a significant decrease in night driving performance (p=0.002), particularly for pedestrian recognition (38% reduction).
Conclusions :
Mesopic tests of visual function, such as motion sensitivity and mesopic high contrast VA, were better predictors of night driving performance in older adults, compared to standard photopic vision tests. These findings inform the development of evidence-based vision testing protocols for older adults reporting vision-related night driving difficulties.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.