Ischemic optic neuropathy is a condition that occurs when blood flow to the optic nerve is reduced or blocked, leading to damage. This can result in sudden vision loss, often in one eye. The condition is typically associated with risk factors such as high blood pressure, diabetes, and certain autoimmune diseases. There are two main types: anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). AION is more common and usually affects the front part of the optic nerve, while PION affects the back part. Diagnosis often involves a comprehensive eye examination and imaging tests.