This is the second edition of the book: OCT and imaging in diseases of the central nervous system. The President of the Foundation for the Advancement of Ophthalmology "Ophthalmology 21", Prof. Andrzej Grzybowski, together with Dr. Piero Barboni, present the state-of-the-art using optical coherence tomography (OCT) to record neuronal loss in the retina. Detailed information on OCT imaging and interpretation is provided to assess disease progression in numerous neurodegenerative disorders and as a biological marker of neuroaxonal damage. The book discusses how retinal examination can help diagnose and monitor disorders such as multiple sclerosis, Parkinson's disease, Alzheimer's disease, intracranial hypertension, Friedreich's ataxia, schizophrenia, hereditary optic neuropathy, glaucoma and visual impairment. This book convincingly demonstrates that the eye is indeed the 'window to the brain'.