Non-arteritic anterior ischaemic optic neuropathy (NAAION) is a condition where blood flow to the optic nerve is suddenly reduced, causing damage and sudden vision loss, like a stroke affecting the optic nerve.
Although typically described as happening in one eye, in my limited experience of helping patients with this problem, the other eye often soon follows.
It is often linked to factors including high blood pressure, high cholesterol, diabetes, heart or blood vessel disease. It can also be triggered by a sudden drop in blood pressure, especially at night, reducing blood flow to the optic nerve head.












