The chapter begins by discussing optic nerve head anatomy and aqueous fluid dynamics, before covering the key clinical skills, namely optic nerve head assessment in glaucoma, tonometry and pachymetry , gonioscopy, and perimetry. It also covers the key areas of clinical knowledge, including ocular hypertension, primary open-angle glaucoma, acute angle closure, normal-tension glaucoma, steroid-induced glaucoma, traumatic glaucoma, inflammatory glaucomas, pseudoexfoliative and pigmentary glaucoma, neovascular glaucoma, malignant glaucoma, iridocorneal endothelial syndrome and iridocorneal dysgenesis, ocular hypotensive agents, laser therapy for glaucoma, and glaucoma surgery. The chapter concludes with three case-based discussions, on open-angle glaucoma, angle closure glaucoma, and steroid glaucoma.