Cardiac emboli: Thrombotic emboli arising from the heart may also cause luminal obstruction of the retinal, ophthalmic, and/or ciliary arteries, causing decreased blood flow to the ipsilateral retina; examples being those arising due to (1) atrial fibrillation, (2) valvular abnormalities including post-rheumatic valvular disease, mitral valve prolapse, and a bicuspid aortic valve, and (3) atrial myxomas. Temporary vasospasm leading to decreased blood flow can be a cause of amaurosis fugax. Generally, these episodes are brief, lasting no longer than five minutes, and have been associated with exercise. These vasospastic episodes are not restricted to young and healthy individuals. "Observations suggest that a systemic hemodynamic challenge provoke[s] the release of vasospastic substance in the retinal vasculature of one eye." Giant cell arteritis: Giant cell arteritis can result in granulomatous inflammation within the central retinal artery and posterior ciliary arteries of eye, resulting in partial or complete occlusion, leading to decreased blood flow manifesting as amaurosis fugax. Commonly, amaurosis fugax caused by giant cell arteritis may be associated with jaw claudication and headache. However, it is also not uncommon for these patients to have no other symptoms. One comprehensive review found a two to nineteen percent incidence of amaurosis fugax among these patients. Systemic lupus erythematosus
Periarteritis nodosa
Eosinophilic vasculitis
Hyperviscosity syndromePolycythemia
HypercoagulabilityProtein C deficiency
Antiphospholipid antibodiesAnticardiolipin antibodies
Lupus anticoagulant
Thrombocytosis
Subclavian steal syndrome
Malignant hypertension can cause ischemia of the optic nerve head leading to transient monocular visual loss. Drug abuse-related intravascular emboli
Iatrogenic: Amaurosis fugax can present as a complication following carotid endarterectomy, carotid angiography, cardiac catheterization, and cardiac bypass.
Ocular origin
Ocular causes include:

Iritis
Keratitis
Blepharitis
Optic disc drusen
Posterior vitreous detachment
Closed-angle glaucoma
Transient elevation of intraocular pressure
Intraocular hemorrhage
Coloboma
Myopia
Orbital hemangioma
Orbital osteoma
Keratoconjunctivitis sicca testing

Neurologic origin
Neurological causes include:

Optic neuritis
Compressive optic neuropathies
Papilledema: "The underlying mechanism for visual obscurations in all of these patients appear to be transient ischemia of the optic nerve head consequent to increased tissue pressure. Axonal swelling, intraneural masses, and increased influx of interstitial fluid may all contribute to increases in tissue pressure in the optic nerve head. The consequent reduction in perfusion pressure renders the small, low-pressure vessels that supply the optic nerve head vulnerable to compromise. Brief fluctuations in intracranial or systemic blood pressure may then result in transient loss of function in the eyes." Generally, this transient visual loss is also associated with a headache and optic disk swelling. Multiple sclerosis can cause amaurosis fugax due to a unilateral conduction block, which is a result of demyelination and inflammation of the optic nerve, and "...possibly by defects in synaptic transmission and putative circulating blocking factors." Migraine
Idiopathic Intracranial Hypertension
Intracranial tumor
Psychogenic

Diagnosis
Despite the temporary nature of the vision loss, those experiencing amaurosis fugax are usually advised to consult a physician immediately as it is a symptom that may herald serious vascular events, including stroke. Restated, "because of the brief interval between the transient event and a stroke or blindness from temporal arteritis, the workup for transient monocular blindness should be undertaken without delay."