The Optic Nerve in Glaucoma

To recognize and to assess glaucomatous changes at the optic nerve, it is important to know the characteristics of the normal optic disc. As in the other biological variables, the appearance of the optic disc varies widely among healthy individuals. This fact is complicate the recognition of the pathological changes. ‘Optic Disc’ is frequently used to describe the portion of the optic nerve clinically visible on examination. This, however, may be slightly inaccurate as ‘disc’ implies a flat, 2 dimensional structure without depth, when in fact the ‘optic nerve head’ is very much a 3 dimensional structure which should ideally be viewed stereoscopically.