Virtual shopping increasingly relies on interaction modalities that bind perception to action. We test how coupling gaze with manual action ("eye+hand") versus hand-only selection shapes consumer behavior in immersive retail. In a controlled laboratory experiment (N = 171) set in a VR supermarket, participants completed standard shopping tasks under one of the two modalities. The eye+hand condition elicited greater exploratory behavior (higher variety seeking) and stronger approach outcomes (greater spending), alongside more favorable subjective evaluations (higher satisfaction and loyalty intentions) than hand-only control. Mediation analyses indicate a sequential mechanism: eye+hand input increases perceived interactivity—a sense that the environment is responsive to one's moment-to-moment intentions—which in turn heightens perceived ease of use, and these experiential states translate into downstream behavioral and evaluative outcomes. Framed within perception-action coupling and embodied cognition accounts, results suggest that aligning oculomotor attention with action affordances reduces friction, amplifies agency, and encourages exploratory choice in virtual environments. The findings advance consumer and cognitive psychology by isolating how an interaction primitive (gaze-contingent control) reshapes attentional engagement and decision dynamics in VR, with implications for theories of fluency, autonomy, and reward-driven exploration in digitally mediated shopping.