Sudden Visual Loss

Updated: Apr 04, 2023
  • Author: Jean Deschênes, MD, FRCSC; Chief Editor: Edsel B Ing, MD, PhD, MBA, MEd, MPH, MA, FRCSC  more...
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Sudden visual loss has an extensive differential diagnosis. Determining the etiology is guided by variables such as patient age, lateralization of symptoms, time course of vision loss, and associated symptoms, including the presence or absence of pain. In general, monocular vision loss indicates an ocular problem or a problem anterior to the optic chiasm, and the vision loss may respect the horizontal midline.

Binocular vision loss usually is cerebral in origin and often respects the vertical midline. Transient vision loss lasting seconds is suspicious of an embolic phenomenon, whereas vision loss lasting on the order of >15 minutes typically, although not always, more characteristic of migraines. [1]  Sudden-onset painless vision loss often is ischemic in origin. However, if accompanied by headache, sudden vision loss can result from giant cell arteritis (GCA) and pituitary apoplexy. Vision loss with pain upon eye movement in young patients should prompt consideration of optic neuritis.

Symptoms of vision loss have been described as a gradually descending gray-black curtain or as blurring, fogging, or dimming of vision and can last a few minutes to hours. The presentation of vision loss ranges from a single episode to multiple episodes per day; recurrences may continue for years and frequently occur over seconds to hours.

Numerous causes of sudden visual loss are recognized. [2, 3] Vision loss with positive scotoma may be seen with migraine. Vision loss with negative scotoma may be seen with amaurosis fugax or retinal transient ischemic attack. Ischemia, often via mechanical obstruction, can affect any aspect of the visual system and commonly occurs among individuals with atherosclerotic disease, such as coronary artery disease and peripheral vascular disease or atrial fibrillation. Sudden changes in refractive error may be associated with diabetes mellitus or shallowing of the anterior chamber due to certain medications, including topiramate. Corneal edema due to endothelial decompensation or hydrops may cause abrupt vision loss. Cataracts encroaching on the visual axis may be interpreted by patients as sudden vision loss.

Other etiologies of sudden visual loss include infection/inflammation, vitreous hemorrhage, [4] retinal detachment, [5] GCA and other vasculitis, [6] trauma, and idiopathic causes.

The management of sudden vision loss is directed at the underlying etiology.



Ischemia compromises cell metabolism by reducing delivery of oxygen and other important nutrients to tissues. The resulting functional deficit may be temporary or permanent, depending on the degree of damage. Nomenclature of eye ischemia as given by Hedges includes the following [7] :

  • Transient visual obscurations (TVO) - Episodes lasting seconds that are associated with papilledema and increased intracranial pressure
  • Amaurosis fugax - Brief, fleeting attack of monocular partial or total blindness that lasts seconds to minutes [2]
  • Transient monocular visual loss (TMVL) or transient monocular blindness (TMB) - A more persistent vision loss that lasts minutes or longer
  • Transient bilateral visual loss (TBVL) - Episodes affecting 1 or both eyes or both cerebral hemispheres and causing visual loss
  • Ocular infarction - Persistent ischemic damage to the eye, resulting in permanent vision loss

Transient vision loss can result from emboli originating from the heart, carotid artery, aorta, or peripheral vasculature. [8] TMVL can also result from arteritis, which causes inflammation of arteries and causes end organ ischemia. [9]




The estimated incidence of TMVL is 14 per 100,000 people per year. [10, 11]


TMVL in a person younger than 45 years may be benign; many attacks are probably vasospastic or due to migraine.

TBVL almost always is associated with severe occlusive disease of the internal carotid artery (ICA), aortic arch, or vertebral circulation with occipital lobe ischemia.

Patients with ICA disease often have other systemic evidence of atherosclerosis, such as coronary and peripheral vascular disease. Other risk factors include smoking, hypercholesterolemia, and hypertension.


Whites, especially men, have a high incidence of ICA-origin atherosclerosis.

Blacks and Chinese and Japanese persons have a higher incidence of intracranial occlusive disease.


A strong male predominance (2:1) exists among patients with severe ICA disease.



The prognosis of sudden visual loss depends on the etiology.


Patient Education

Patients with sudden visual loss should seek professional care.

For excellent patient education resources, visit eMedicineHealth's Eye and Vision Center and Cholesterol Center. Also, see eMedicineHealth's patient education articles Anatomy of the EyeHigh Cholesterol, and Cholesterol FAQs.