Impact of ambient light intensity and display brightness on visual behavior based on eye tracking technology

DU Jian; YANG Liu; GE Hanxiao; SUN Xianghong; ZHANG Yishuang; LI Xiaoyan; HAO Yaokun; XIONG Duanqin

doi:10.3969/j.issn.2097-1753.2025.05.002

Abstract：Objective To investigate the impact of varying ambient light intensity and display brightness on pilots' visual behavior using eye-tracking technology.Methods Nineteen military pilots were selected as the subjects between July 2024 and December 2024.Under three levels of ambient light intensity(dim light,medium-intensity light,and strong light),the subjects adjusted the display brightness to the three levels(minimum,moderate,and maximum).Data on their pupil diameter,saccade duration,blink duration,and gaze trajectory was collected by eye-tracking system.Results In the dim light environment,the pupil diameter was larger when the display brightness was at the minimum level compared to the moderate and maximum levels(P=0.010,＜0.001),and it was also larger at the moderate level than at the maximum level(P＜0.001).Under any of the display brightness levels,the pupil diameter in the dim light environment was significantly larger than in either the medium-intensity or strong light environment(all P＜0.001).Under the maximum display brightness,the pupil diameter in the medium-intensity light environment was larger than in the strong light environment(P=0.012).The effects of ambient light intensity and display brightness on the saccade duration were insignificant(all P＞0.05).In the medium-intensity light environment,the blink duration was significantly shorter than in the strong light environment(P=0.019).The gaze trajectories varied with ambient light intensity.Paths were more tortuous with more fixation points in the dim and the strong light environments,whereas they were more direct in the medium-intensity light environment.Conclusion The results suggest that both ambient light intensity and display brightness impact the pupil diameter rather than on the saccade duration.Ambient light intensity influences the blink duration,while display brightness has little effect.Gaze trajectories also vary widely under varying ambient light intensities.These findings can provide a reference for the optimized design of light environments and display brightness.