Cost-of-illness studies determine the total financial burden of a disease by considering direct and indirect costs, including medication, diagnostics and surgery. Studies of resource use and costs associated with primary open-angle glaucoma have used varying methodologies. Most have focused on consumption of healthcare resources at various stages of disease to anticipate costs. The direct costs associated with the disease often continue to increase as glaucoma progresses from the earliest to most advanced stages. Determinations of the costs associated with glaucoma progression and prevention should also incorporate the chance of patient non-compliance with treatment. Since glaucoma severity most often correlates with increased costs, minimizing or halting visual field loss and increasing patient treatment compliance may all contribute to a reduction in the overall economic burden of glaucoma.