We used a visual world paradigm with British Sign Language (BSL) to test the methodology with a visually perceived language, and gain insight into the time course of BSL processing at the lexical level. Subjects were tracked while viewing four object pictures and a BSL video. One picture was (semantically or phonologically) related to the target sign, with target pictures present on some trials and absent on others. Like previous spoken language studies, sign perceivers looked significantly more often towards related distracters than unrelated after the onset of the target sign, regardless of target picture presence. However, results indicate important differences in the time course of looks compared to speech, with gaze to pictures infrequent (due to attention to video) and earlier, often before actual sign onset. This last occurs because, unlike speech, the preparation phase (in which sign handshape and location are attained) is visible, allowing earlier cohort activation.