The Optic Nerve: Anatomy and Pathology.

The optic nerve is the second cranial nerve but is not a true cranial nerve. Instead, it's an extension of the brain parenchyma. The optic nerve transmits electrical impulses from the retina to the brain, which will be processed in visual information. Often, the clinical definition of a lesion in the optic nerves is not clear, and magnetic resonance imaging (MRI) plays a crucial role. In addition, the optic nerves can be affected by several diseases, such as congenital malformations, inflammatory, vascular, and neoplastic diseases. This article aims to review the optic nerve anatomy, discuss the best MRI techniques to evaluate each nerve segment, and demonstrate the imaging aspect of the diseases that most commonly affect it.