The optical radiation indicates the beam of nervous fibers which connects the side geniculate Corps Thalamus to the visual Cortex ipsilatéral.

These nervous ways contribute to the transmission of the visual information Consciente so that lesion of an optical radiation led to a Hémianopsie, the loss partial or total of the vision in the hemisphere concerned.

There is an optical radiation in each hemisphere, one thus speaks in general about the optical radiations in the plural. Discovered by Louis Pierre Gratiolet, one also indicates them under the name of radiations of Gratiolet .