Anterior ischemic optic neuropathy (AION) is a condition that occurs when blood flow to the optic nerve is reduced, leading to vision loss. This can happen due to various factors, including high blood pressure, diabetes, or arterial inflammation. AION is often characterized by sudden vision changes, typically in one eye. There are two main types of AION: non-arteritic AION and arteritic AION. Non-arteritic AION is more common and usually occurs without inflammation, while arteritic AION is associated with conditions like giant cell arteritis, which involves inflammation of the blood vessels. Early diagnosis and treatment are crucial for managing the condition.