Glaucoma is a typical optic neuropathy mainly caused by elevated intraocular pressure (IOP). In recent years, with the advances in understanding of glaucoma and visual sciences, and the development of a neurological cross-discipline and neuroimaging technology, the question about the nature of glaucoma has been raised. Is glaucoma merely an ocular disease? Is it a disease that begins from the eye, and then involves the whole visual pathway? Or is it a particular central nervous disease, which manifests itself in the eye? The answers to these questions are controversial. Growing evidences have showed that glaucoma is a disease with multi-level, multi-factor damage to the entire visual pathway which involved from optic nerve to the lateral geniculate body, optic radiation and visual cortex. Its mechanisms are complex. We believe that glaucoma is a central nervous system neurodegenerative disease. Recent study showed that the primary damage of glaucoma occurred in central nervous system rather than in the eye. The new generation of concept steps forward in the knowledge of the pathogenesis of glaucoma, and may illuminate the potential of neuroprotection in glaucoma management.