Primary open-angle glaucoma (POAG) is a chronic and progressive optic neuropathy characterized by the degeneration of optic nerve fibers and gradual loss of the visual field. It is the most common form of glaucoma and one of the leading causes of irreversible blindness worldwide. The disease is generally asymptomatic in its early stages, which complicates early diagnosis. Elevated intraocular pressure is the main risk factor, but other aspects such as genetic predisposition and vascular dysfunction also contribute to its pathogenesis. Early diagnosis and treatment are essential to preserve vision and patient quality of life. This literature review was conducted using scientific publications retrieved from the Virtual Health Library (VHL), PubMed, CAPES Journals Portal, and the Scientific Electronic Library Online (SciELO), with no time restrictions. Primary open-angle glaucoma is a progressive and silent ocular disease and a major cause of irreversible blindness. Elevated intraocular pressure, together with genetic and vascular factors, contributes to optic nerve degeneration. Early diagnosis is challenging due to the absence of initial symptoms, making screening in risk groups essential. Treatment aims to control intraocular pressure through medication, laser therapy, or surgery, combined with continuous follow-up. Patient adherence and education are fundamental to slowing disease progression and preserving vision.