Distinguishing between sensory experiences elicited by external stimuli and an animal's own actions is critical for accurate perception. However, the diversity of behaviors and their complex influences on the senses make this distinction challenging. Here, we show that a combination of self-motion cues modulates visual processing in the superficial superior colliculus (sSC), the brain's first visual relay. We uncovered a projection from the ventral lateral geniculate nucleus to the sSC in mice that functions as a corollary discharge hub, conveying inhibitory signals about translational optic flow and motor dynamics, including saccades, locomotion, and pupil size. Activation of this projection potently dampens visual responses and concurrently drives corresponding motor actions that resemble motor prediction errors; suppression disrupts action-specific visual perception. Our results show that visual signals undergo continuous refinement at the earliest stages through the convergence of self-motion information, ensuring accurate visual perception and visuomotor control.