Diffuse Illumination Device to Improve Mesopic Contrast Sensitivity in Drivers.

Abstract

Purpose: To evaluate the influence of a diffuse illumination device located outside the " eld of vision that provokes a controlled pupillar miosis, on the contrast sensitivity in drivers tested in mesopic conditions. Method: Cross-sectional prospective observational study in which contrast sensitivity by Pelli-Robson Test (CS) was evaluated in 49 drivers under 40 years old and 60 drivers over 40. The study was carried out in a simulated setting for night driving with and without the interposition of the diffuse illumination device. The mesopic contrast sensitivity was measured in the absence or presence of glare. Results: In both age groups, a statistically signi" cant improvement of contrast sensitivity was exhibited. In drivers aged over 40, baseline (BS) Pelli-Robson contrast sensitivity scores were: BS=0.83±0.3 and BSg=0.59±0.3 in absence and in presence of glare, whereas values for the interposition of diffuse illumination device (D) were: D=0.93±0.3 (p<0.05) and Dg=0.62±0.3 (p<0.05). On the other hand, in drivers aged under 40, baseline contrast sensitivity values were: BS=1.09±0.2 and BSg=0.95±0.3 whereas the interposition of the mentioned system showed the following values: D=1.27±0.3 (p<0.05) and Dg=1.11±0.3 (p<0.05). Conclusion: Using a diffuse illumination device in the interior of the vehicle provides significant improvement in contrast sensitivity.