Visual Function and Driving Performance Under Different Lighting Conditions in Older Drivers: Preliminary Results...

Area of Science:

• Ophthalmology and Vision Science
• Gerontology
• Transportation Safety

Background:

• Age-related vision decline is a critical factor in nighttime driving accidents among older adults.
• The precise impact of varying light conditions on vision and driving performance in this demographic is not well understood.

Purpose of the Study:

• To investigate the relationship between visual function and driving performance in drivers aged 60 and above.
• To assess these relationships across three distinct lighting conditions: daytime (photopic), nighttime (mesopic), and nighttime with glare, using a high-fidelity driving simulator.

Main Methods:

• Participants (N=20, age 60+) underwent visual function tests including visual acuity (VA), contrast sensitivity function (CSF), and visual field map (VFM).
• Simulated driving performance metrics (speed, lane position, reaction time) were recorded under photopic, mesopic, and mesopic with glare conditions.
• Pearson correlations were used to analyze associations between visual function metrics (e.g., area under the log CSF) and driving performance.

Main Results:

• Reduced visual acuity and contrast sensitivity were linked to poorer driving performance, including increased speed variability and lane position deviations, particularly under nighttime and glare conditions.
• Impaired visual field function correlated with slower speeds, increased speed variability, and longer reaction times during nighttime driving.
• Specific visual function deficits showed significant associations with driving impairments under mesopic and glare conditions, underscoring the heightened risk at night.

Conclusions:

• Visual function significantly influences driving performance in older adults, with diminished capacity under low light and glare posing greater risks.
• These findings suggest that age-related vision changes have a differential impact on driving safety depending on lighting conditions.
• Further research with larger cohorts is recommended to validate these preliminary findings and inform safety interventions.