This study examines the extent to which ambient light levels affect the transient visual effectiveness of a non-lethal laser radiation on human eyes. A typical 532-nm laser dazzler was selected to simulate the scenario in a military-specific mission. A transient visual effect detection and evaluation system was used as a visualisation tool to perform a series of laser dazzle simulation tests that involved varying the laser radiation distances and target contrasts under ambient light levels that ranged from 10−3 lx to 103 lx. In the experiments, we captured images showing the effect of a laser dazzle on human eyes and calculated parameters that can determine the transient visual effect. After theoretical verification and analysis, the results show that different levels of ambient light significantly affect the transient visual effect of non-lethal laser radiation and that the laser radiation distance and target specificity also affect the transient visual effect to varying degrees. In particular, the laser sample demonstrates optimal levels of dazzling when the ambient illumination ranges from 0.1 lx to 10 lx, the radiation distance is close to 100 m and the target contrast is 40%. We argue that the influence pattern of the ambient light level on the pupil diameter of the human eye and the degree of dazzling perception are the main reasons for the results. The conclusions serve as a reference for the application of a non-lethal laser radiation in military-specific missions.