Glaucoma is a chronic disease that if left untreated leads to vision loss in the patient. It is estimated that by 2020, there will be 80 million glaucoma patients, of which 20 million are angle-closure patients. It is considered a very big public health problem. It affects about 50 million people with the highest frequency in people over the age of 50. We distinguish between open-angle and closed-angle glaucoma. It is very important to recognize the symptoms of this disease in time so that complications can be prevented in time. When diagnosing glaucoma, doctors use a series of specific tests. At the first arrival, the patient has a medical history and is examined with a gonioscope. Gonioscopy is a specific examination in which a gonioscope examination reveals a slight narrowing of the angle between the cornea and iris, which makes it difficult for the eye to drain and leads to an increase in intraocular pressure, which is the most common cause of glaucoma. The gold standard in measuring intraocular pressure is Goldmann applanation tonometry. Measurement of intraocular pressure, gonioscopy findings, visual field testing and observation of the pathological appearance of the optic papilla and damage to the nerve fiber layer are the most common criteria in diagnosing glaucoma.