Abstract
Purpose :
To evaluate the influence of an alcohol consumption in visual and driving performance, since driving after drinking is a worrying aspect worldwide.
Methods :
A total of 10 individuals of different ages took part in the study (30.6±11.9 years). They underwent two sessions: the first under normal conditions and the second with an alcohol consumption of 450 ml of red wine. Participants were divided in two groups: subjects with a breath-alcohol content (BrAC) of 0.25mg/l or lower, and subjects with a BrAC>0.25 mg/l, as 0.25 mg/l is the legal limit for driving in Spain. We evaluated the contrast-sensitivity function (CSF), the straylight in the eye and the ocular optical-quality by measuring the MTF cut-off, the Strehl ratio and the objective scatter index for a 4mm pupil size. Driving performance was evaluated with the Simax Driving Simulator in three different environments: dual carriageway, two-lane mountain road, and inner-city.
Results :
After alcohol consumption, a deterioration of the CSF was found for the group with BrAC≥0.25 mg/l (n=4). For the group with BrAC<0.25 mg/l (n=6), the CSF was deteriorated but not significantly (p>0.05). The optical quality was also deteriorated for both groups, due mainly to a deterioration of the tear film and a larger pupil size. The straylight effect was stronger for both groups (p>0.05). The mean speed was lower on the dual carriageway (p>0.05), and the distance driving on the shoulder and the number of times driving on the shoulder were also higher (p<0.05).
On the dual carriageway, individuals with better contrast sensitivity for high spatial frequencies had a lower number of times driving on the shoulder (r=-0.5) as well as for individuals with a higher rate of straylight (r=0.4). In mountain road, individuals with best results in highest frequencies drove faster (r=0.8), and also those who had better ocular optical quality and higher straylight values (r=0.5). Finally, in the inner-city, we found a lower number of collisions and stops for individuals who performed better for higher spatial frequencies in contrast sensitivity (r=-0.6).
Conclusions :
We have found a correlation between visual tasks (contrast-sensitivity function, straylight effect, and optical quality) and driving skills. This demonstrates that alcohol consumption deteriorates vision and driving skills, indicating that driving after drinking becomes a more difficult and dangerous task.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.