Deterioration of binocular vision after alcohol intake influences driving performance

Abstract

In this study, we assessed the influence of moderate alcohol intake on binocular vision, vergence system and simulated driving performance by analyzing the interactions between visual deterioration and driving variables. Thirty young healthy subjects were recruited. For the analysis, we measured: visual function (visual acuity and stereoacuity), phorias and fusional reserves. Also, we checked Sheard’s and Percival’s criteria at near and far. The accommodative convergence/accommodation (AC/A) ratio was calculated and vergence facility was also obtained at near. A driving simulator was used to assess driving performance under natural conditions and after alcohol consumption with a breath alcohol content of 0.40 mg/l. Alcohol intake significantly reduced binocular visual performance and vergence function, except for vertical phorias, horizontal phoria at near and Sheard’s and Percival’s criteria at near. Driving performance parameters also presented a statistically significant deterioration after alcohol consumption. A statistically significant correlation was found between the deterioration in overall visual function and overall driving performance, highlighting the influence of the visual deterioration on the driving performance. Moderate alcohol consumption impairs binocular visual and simulated driving performances, implying a greater safety hazard. In addition, deteriorations in binocular visual function and vergence correlated with simulated driving impairment, which indicates that the deterioration of binocular vision due to alcohol consumption affects driving, thus reducing road safety.

Effect of interocular differences on binocular visual performance after inducing forward scattering

“…Finally, in line with the OIDS calculation and other studies, 18,36,57,63 an overall binocular summation score (OBSS) was also calculated for the visual functions analysed (VA, CSF and VDI), and for all of the filter conditions. To do this, we averaged the z ‐scores of these visual function variables for each filter condition.…”

“…For all the variables, the more positive the score, the greater the interocular differences. Z-scores have been widely used 18,36,57,63 and are a measurement of how many standard deviations an individual value lies away from the group mean.…”

“…42,73,83,84 Stereoscopic perception allows the visual system to see the surrounding environment in depth, and is paramount in critical complex tasks such as driving. 18,36,57 We produced a large range of interocular differences, primarily using Bangerter foils and the BPM2 filter before the dominant eye. These relationships are in line with other studies.…”

“…Assessing binocular visual performance is an important aspect of a visual examination. In order to evaluate binocular vision, the effect of binocular summation on different visual functions, [1][2][3][4][5][6][7][8][9] as well as stereopsis, [10][11][12][13][14][15][16][17][18] has been examined. Binocular summation is defined as the superiority of the binocular system with respect to monocular viewing in terms of visual function.…”

Changes in Visual Performance under the Effects of Moderate–High Alcohol Consumption: The Influence of Biological Sex

“…In this sense, some works have shown that exophoria (increased at near vision tasks under the effects of alcohol) has a lesser effect on stereopsis, although it may vary depending on the magnitude of the exophoria [ 10 , 11 ]. However, esophoria (increased at distance) has a greater influence [ 8 , 12 , 13 ]. The effects of alcohol consumption on other visual functions, such as halo perception (and other night vision dysphotopsia) and objective measurements (such as the retinal image quality) have been less studied.…”