Abstract
OBJECTIVE: Difficulties in night driving due to deficits in visual function are a common problem among older drivers. Signage, hazards, and road markings can be more difficult to identify for those with presbyopia, especially in nighttime conditions that include glare from headlights. This study evaluated the visual function and driving abilities of participants in various lighting conditions to find efficient and effective testing procedures for predicting how older individuals will perform in night driving conditions. METHODS: A driving simulator study was conducted to investigate the relationship between driving performance measures and visual function measures in different lighting conditions. Participants were examined in a laboratory setting to measure visual acuity and contrast sensitivity in bright light, dim light, and dim light with glare conditions. The participants were asked to drive in a driving simulator in simulated day, night, and night with glare conditions. Analysis using a linear mixed model was performed across the lighting conditions. RESULTS: There are statistically significant relationships between the experimental variables, with age being an important factor. Age was found to have a statistically significant effect on the standard deviation of lateral position, which is a measure of vehicle control. Age was also found to have a statistically significant effect on reaction time and accuracy of a secondary identification task. Visual acuity and contrast sensitivity were found to have a statistically significant effect on mean velocity. CONCLUSIONS: Results suggest that visual acuity alone is insufficient to fully describe visual function for predicting performance in a driving task, but the ideal variables for prediction of performance in a night driving situation are not clear.