The idea that visually-guided action is independent of visual perception has been supported by neurological, neuropsychological and behavioural studies (Crawford et al. 2004; Culham et al. 2003; Goodale and Milner 1992; Goodale et al. 1991; Shmuelof and Zohary 2005). In healthy subjects, evidence for this distinction has come from psychophysical studies of the effects of visual illusions on perceptual judgments and object-directed grasping (Aglioti et al. 1995; Haffenden et al. 2001). This evidence however, is limited by the fact that virtually all studies have involved right-handed subjects using their dominant hand, which is presumably controlled by the left hemisphere. There is tentative evidence from neurological studies that the left hemisphere may in fact play a special role in the integration of visual and motor information during grasping (Perenin and Vighetto 1988). We designed two experiments to test this idea. The first experiment involved pictorial illusions, which are known to have robust effects on perceptual judgments but little influence on grasping (Aglioti et al. 1995; Haffenden et al. 2001). Right- and left-handed subjects reached out and grasped objects embedded in two different visual illusions with either their dominant or their non-dominant hand. For both right- and left-handed subjects, precision grasping with the left hand, but not with the right, was affected by the illusions. In a follow-up experiment, we examined precision grasping in a more natural setting and showed that left-handed subjects use their non-dominant (right) hand significantly more as compared to right-handed subjects. We conclude that visuomotor mechanisms encapsulated in the left hemisphere play a crucial role in the visual control of action, and that this hemispheric specialization evolved independently of handedness.