The point where some of the fibres from both optic nerves cross over to the opposite side, forming an X-shaped structure. Sensory information from the right side of both the right and left eye is transmitted to the right primary visual cortex in the brain (via the right lateral geniculate nucleus), while information from the left side of each eye is carried via the left lateral geniculate nucleus to the left primary visual cortex. Additional neurons project from the primary visual cortex to connect to centres elsewhere in the cortex responsible for higher-order visual processing and integration. Thus each half of the brain receives sensory information from both eyes.