Aim – to analyze the structure, risk factors, and causes of ischemic optic neuropathy (ION). Material and methods. A total of 239 patients (303 eyes) with ION and 98 patients (185 eyes) with optic disc drusen were examined. All ION patients underwent general clinical assessment. Those under 50 years of age were also tested for antiphospholipid markers and gene polymorphisms of the coagulation system. Results. All patients were found to be exposed to two or more modifiable risk factors of ION. A total of 47.1% of cases were judged as being at anatomical risk of anterior ION (AION) with the cup-to-disc ratio in the second eye of less than 0.15 (of less than 0.25 in 53% of cases). Of 98 patients (185 eyes) with optic disc drusen, 5.4% of cases (10 eyes) developed AION. As many as 22% of ION patients were under 50 years of age. Of them, in 32% primary APS was diagnosed, in 3.6% - secondary (in the presence of SLE); all cases were positive for polymorphisms of the coagulation system that determine genetic predisposition to ION (indeed, the frequency of the latter was significantly higher in these patients than in the control group). Conclusion. Ischemic optic neuropathy is an optic nerve disorder that requires thorough medical history taking and comprehensive assessment of the patient in order to identify the causes and risk factors of this disease as well as accompanying pathologies.