Open AccessEffects of Smoking Cannabis on Visual Function and Driving Performance. A Driving-Simulator Based Study
Author(s) -
Sonia Ortiz-Peregrina,
Carolina Ortíz,
Joseph J. Torres,
José María López Jiménez,
Rosario G. Anera
Publication year - 2020
Publication title -
international journal of environmental research and public health/international journal of environmental research and public health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.747
H-Index - 113
eISSN - 1661-7827
pISSN - 1660-4601
DOI - 10.3390/ijerph17239033
Subject(s) - cannabis , driving simulator , stereoscopic acuity , poison control , visual acuity , injury prevention , human factors and ergonomics , audiology , occupational safety and health , psychology , medicine , simulation , computer science , medical emergency , ophthalmology , psychiatry , pathology
Cannabis is the most widely used illegal drug in the world. Limited information about the effects of cannabis on visual function is available, and more detail about the possible impact of visual effects on car driving is required. This study investigated the effects of smoking cannabis on vision and driving performance, and whether these effects are correlated. Twenty drivers and occasional users were included (mean (SE) age, 23.3 (1.0) years; five women). Vision and simulated driving performance were evaluated in a baseline session and after smoking cannabis. Under the influence of cannabis, certain visual functions such as visual acuity ( p < 0.001), contrast sensitivity ( p = 0.004) and stereoacuity (far, p < 0.001; near, p = 0.013) worsened. In addition, there was an overall deterioration of driving performance, with the task of keeping the vehicle in the lane proving more difficult ( p < 0.05). A correlation analysis showed significant associations between driving performance and visual function. Thus, the strongest correlations were found between the distance driven onto the shoulder and stereoacuity, for near ( ρ = 0.504; p = 0.001) and far distances ( ρ = 0.408; p = 0.011). This study provides the first evidence to show that the visual effects of cannabis could impact driving performance, compromising driving safety. The results indicate that information and awareness campaigns are essential for reducing the incidence of driving under the influence of cannabis.