[The pupil and retrogeniculate visual pathway. Overview].

Classically, the pathway serving the pupillary light reflex is considered to be a simple reflex arc consisting of the retinal ganglion cells, intercalated neurons in the midbrain, the oculomotor nerve and short ciliary nerves. Investigations in patients with lesions of the postgeniculate visual pathways showed that the pupillary pathway is more complex than previously assumed. The retrogeniculate visual pathway is also involved in the pupillary light reaction.