Understanding the mechanisms of consciousness is a major and challenging question in neuroscience. Studies of the neural correlates of visual awareness have benefited from using bistable phenomena such as binocular rivalry, in which conscious perception fluctuates with constant visual inputs. Non-invasive neuroimaging techniques, especially functional MRI, made it possible to directly investigate the neural correlate of consciousness in the human brain. The focus of this review is on studies related to the unconscious visual information processing in the parallel visual pathways as well as in the subcortical visual structures. Future research to explore the neural mechanisms of consciousness will need to be highly interdisciplinary and integrative, over a broad range of spatiotemporal scales and across different species.