Glaucoma had affected over 7 million people in 2020, causing 3.60 million to become blind. Glaucoma is a term describing a group of ocular disorders characterized by optic neuropathy due to a multifactorial etiology with the only modifiable risk factor being the intraocular pressure. It is a group of disorders and not a single entity, and all forms are potentially progressive that can lead to blindness. Irrespective of the causal mechanism, the primary site of neurological injury is at the optic nerve head. Glaucomatous optic neuropathy is clinically characterized by excavation and enlargement of the optic cup, with focal or generalized thinning of the neuroretinal rim. Pathologically, there is neurodegeneration of the retinal ganglion cells. This chapter briefs about the different mechanisms of glaucoma and the treatment modalities of the same, with emphasis on the etiopathology of the process.