The optic nerve is a primary reference for those ophthalmologists and researchers interested in its anatomy and physiology, in the most recent diagnostic techniques, as well as in the clinical management of optic nerve disorders. The book provides a detailed description of the structure and functioning of the optic nerve and attempts at clarifying how anomalies in its development are related with tumor development. The book surveys the most recent diagnostic techniques, such as spectral domain optical coherence tomography, and highlights how these techniques can be employed to evaluate optic nerve layers as well as lesions compressing the visual pathway. Practical references to optic nerve drusen and the changes in the optic nerve due to diabetic retinopathy are also presented. The book is written in a concise fashion and aims at being a major reference to a broad audience, including students, ophthalmologist consultants, neurologists, researchers, and surgeons concerned with optic nerve diseases.