A major public health problem. Second leading cause of blindness worldwide after cataracts The leading cause of irreversible blindness in African Americans. Asymptomatic until advanced visual field loss occurs. Risk factors Elevated intraocular pressure, advancing age, family history, African ancestry, myopia Diabetes, hypertension. Mechanism remains unclear. Examination: Pressure check, Perimetry (Visual Field), Fundus photography Optical Coherence Tomography. Treatment : lowering intraocular pressure. Initial treatment: topical or oral medications. Advanced treatment: Laser trabeculoplasty Incisional glaucoma surgery: Trabeculectomy, glaucoma drainage implant.