Ischemic optic neuropathy (ION) is the loss of structure and function of a portion of the optic nerve due to obstruction of blood flow to the nerve (i.e. ischemia). ION is typically classified as either anterior ischemic optic neuropathy or posterior ischemic optic neuropathy according to the part of the optic nerve that is affected. The optic nerve is the nerve that transmits visual information from the retina to the brain. ... In medicine, ischemia (Greek ισχαιμία, isch- is restriction, hema or haema is blood) is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. ... Anterior ischemic optic neuropathy (AION) is a medical condition including loss of vision due to damage to the optic nerve. ... This article needs to be cleaned up to conform to a higher standard of quality. ...

References

Dictionary of Eye Terminology, Triad Publishing Company, 1990.