This study examines the impact of lighting conditions (darkness, rotational light and continuous light) on warfighters’ psychophysiological responses and fine motor skills in close-quarter combat (CQC) simulations. The study assessed the rate of perceived exertion, blood lactate concentration, cortical arousal, isometric lumbar and leg strength, and the time required to reload a pistol magazine in 50 male military personnel experienced in international missions. Findings revealed distinct psychophysiological responses correlated with lighting conditions, with significant responses under rotational and no-light scenarios. Notable correlations included the critical flicker fusion threshold with magazine reload time (r = -0.547, p < 0.000) and isometric strength post-CQC with the rate of perceived exertion (r = 0.319, p < 0.009). The study suggests that manipulating lighting conditions ca...