Glaucoma is a group of chronic neurodegenerations that make up the leading cause of irreversible blindness worldwide. Most glaucomas are age-related, with sharp increases in incidence in late middle age. Glaucoma blinds through the progressive dysfunction and degeneration of retinal ganglion cells (RGC): the projection cells of the eye. This disease is often associated with elevated intraocular pressure (IOP), though many patients exhibit glaucomatous pathology in the absence of elevated IOP (normotensive glaucoma). Whether elevated or not, IOP remains the main modifiable risk factor, and reducing IOP is the sole therapeutic target in glaucoma. Given glaucoma’s etiology and epidemiology, it is not surprising that systemic metabolic factors can play a large role in glaucoma risk and severity. Metabolic syndrome factors such as systemic hyper- or hypotension, obesity, high blood viscosity, and defective insulin signaling can increase glaucoma risk through increasing IOP, reducing retinal blood flow, or otherwise impairing retinal energetics. This chapter will introduce glaucoma, discuss the interface between major metabolic factors and glaucoma, touch on some dietary influences and describe glaucoma treatment.