In neuroanatomy, the optic radiation (also known as the geniculocalcarine tract, the geniculostriate pathway, and posterior thalamic radiation) are axons from the neurons in the lateral geniculate nucleus to the primary visual cortex.

If a lesion only exists in one unilateral division of the optic radiation, the consequence is called quadrantanopia, which implies that only the respective superior or inferior quadrant of the visual field is affected.

If both divisions on one side of the brain are affected, the result is a contralateral homonymous hemianopsia.

The upper division: The lower division: A distinctive feature of the optic radiations is that they split into two parts on each side: *Note: In 2009, an anonymous medical doctor edited the "Optic Radiation" Wikipedia article and added the eponymous name "Baum's loop," referring to the dorsal bundle.

Despite the information being unverified, this name subsequently entered scholarly articles and textbooks and persisted until three radiologists discovered the fabrication in 2020.