optic tract

Retinal ganglion cell axons that have passed through the optic chiasm continue as the optic tract, a predominantly white matter structure of the diencephalon. The tract is considered to extend from the optic chiasm and to terminate largely, though not exclusively, in the lateral geniculate complex; other fibres end in the superior colliculus and in further structures of the diencephalon, midbrain, and brainstem. This branching of destinations distinguishes the tract from a simple point-to-point relay, since visual information leaving it reaches both the thalamic route toward cortex and midbrain targets. Its alternative designation is the optic lemniscus, and it is classified as a tract of the diencephalon within the nervous system.