A patient writes:

My friend told me he had a TIA in his left eye, something I had not heard of.   Can you tell me more?

My response:

A TIA (Transient Ischemic Attack) is a brief episode of blood loss to an area of the central nervous system, which results in transient symptoms that then resolve to baseline without injury.  This is opposed to a stroke which leaves damaged nerves and results in residual symptoms.

A TIA in the central retinal artery that supplies blood to the retina (nerve of the eye) will result in transient loss of vision in the affected eye.  Termed Amaurosis Fugax (latin translation ‘darkness fleeting’), the patient experiences complete loss of vision in the eye that is perceived  as a shade being pulled down, but symptoms can vary with a grayness or blackness that lasts for several seconds to minutes.  It resolves completely with normal vision restored.

Amaurosis is a serious condition in that it indicates the potential for future TIA events or even strokes, so an evaluation is essential to determine the cause of the event and to institute preventive measures.

If you have loss of vision in an eye, even if transient, it is an urgent issue that requires attention.  Never ignore such symptoms.   Immediately check each eye by covering the other eye and checking your vision.  Determining if the vision loss is in one eye or is affecting both eyes in the same visual field is an important distinction, so doing this test yourself at the time of symptoms is a key element in diagnosis.   Check out your vision this way and you will help in determining the diagnosis and the proper evaluation to be done.