Vehicle Braking Performance and Saccadic Eye Movement with Different Illuminance Transmission Exposures in Digital Driving Simulation

During driving, the eye moves as we shift the focus of our eye from one point of interest to another point, known as saccadic eye movement. Although the eye movement is not affected under different illuminance conditions during driving, the movement is involved in the ability to drive. This study investigates the correlation between saccadic eye movement and vehicle braking performance when the illuminance transmission was reduced by introducing a neutral density filter in front of the eyes. This is conducted by exposing four levels of illuminance transmission which are 100%, 50%, 30%, and 15% with driving simulation as braking performance is measured. Based on the baseline data from our preceding saccadic investigation on the same subjects using the Dikablis eye tracker, the braking performance is analyzed together with the eye movement data. Twenty-eight young adults with proper license and driving experience, as well as a good history of systemic, ocular, and binocular vision health, are involved in this study. The driving task is conducted via driving simulation, with the subjects instructed to drive naturally. There is no significant correlation between the number of saccadic eye movements and all investigated vehicle braking performances (speed, time, and length) under reduced illuminance transmissions of 30% and 15% (p>0.05). While our previous investigation reveals that the saccadic eye movement is not affected by different illuminance transmissions when driving, this current study concludes that the vehicle braking performance is not correlated with the saccades while driving under those low illuminance exposures.