Transient Vision Loss

Transient vision loss refers to temporary episodes of vision impairment that resolve completely, typically lasting seconds to minutes. While the vision returns to normal, these episodes can be warning signs of stroke, blood vessel problems, or other conditions requiring urgent evaluation.

What Transient Vision Loss Feels Like

People describe these episodes in various ways:

• Like a curtain or shade coming down over vision
• Dimming or graying out of vision
• Complete blackout in one eye
• Blurring that clears when blinking
• Peripheral vision closing in then reopening
• Vision cutting out then returning fully
• Episodes lasting seconds to minutes
• Occurring with standing up, exertion, or randomly
• Single episode or recurring attacks

Types and Causes

Amaurosis Fugax (One Eye)

Transient monocular vision loss (one eye) often indicates vascular problems:

Embolic causes (debris in bloodstream):

• Carotid artery disease—plaque in neck artery breaks off and temporarily blocks eye vessels
• Cardiac emboli—clots from heart (atrial fibrillation, valve disease)
• Giant cell arteritis—inflammation of arteries (medical emergency in older adults)

Blood flow problems:

• Carotid stenosis—narrowing reducing blood flow
• Low blood pressure—insufficient perfusion
• Vasospasm—temporary artery constriction

Bilateral Transient Vision Loss (Both Eyes)

Loss of vision in both eyes suggests causes affecting the brain or both optic nerves:

• Vertebrobasilar insufficiency—reduced blood flow to back of brain
• Occipital lobe ischemia—temporary loss of blood flow to visual cortex
• Papilledema—raised intracranial pressure causing brief visual obscurations
• Migraine with aura—visual disturbances before or during migraine
• Hypotension—low blood pressure episodes

Other Causes

• Positional—vision graying with standing (orthostatic hypotension)
• Exertional—with Valsalva maneuver or exercise
• Gaze-evoked—occurring when looking in certain directions (suggests mass lesion)

When to Seek Emergency Care

What You'll Be Asked in Clinic

Your doctor will ask detailed questions including:

About the episodes:

• How long did the vision loss last?
• Did it affect one eye or both? How do you know?
• Was it partial (like a curtain) or complete blackout?
• How many episodes have occurred?
• Any triggers (standing, exercise, looking in certain direction)?
• Any associated symptoms—headache, dizziness, weakness?

About your health:

• Do you have high blood pressure, diabetes, high cholesterol, or heart disease?
• Have you ever had a stroke or TIA (mini-stroke)?
• Do you smoke?
• Any history of blood clots?
• Are you over 50 and having new headaches or scalp tenderness?
• What medications are you taking?

How Transient Vision Loss Is Diagnosed

Urgent Workup

Given the risk of stroke, evaluation should be prompt:

Eye examination:

• Complete dilated exam looking for emboli in retinal vessels
• Checking for signs of giant cell arteritis

Vascular evaluation:

• Carotid ultrasound—checking for plaque and stenosis
• Echocardiogram—looking for cardiac source of emboli
• Heart rhythm monitoring—detecting atrial fibrillation

Blood tests:

• ESR and CRP—checking for inflammation (giant cell arteritis)
• Complete blood count—looking for blood disorders
• Lipid panel—checking cholesterol
• Glucose and HbA1c—diabetes screening

Brain imaging:

• MRI brain—looking for prior strokes or lesions
• MRA (magnetic resonance angiography)—imaging blood vessels

Treatment Options

Treatment focuses on preventing permanent vision loss or stroke:

For Carotid Disease

• Antiplatelet medication—aspirin or clopidogrel
• Statin therapy—to stabilize plaque and lower cholesterol
• Carotid endarterectomy—surgery to remove plaque if significant stenosis
• Carotid stenting—placing a stent to open the artery

For Cardiac Causes

• Anticoagulation—blood thinners for atrial fibrillation
• Valve repair or replacement—if valve disease is source

For Giant Cell Arteritis

• Immediate high-dose steroids—to prevent permanent blindness
• Tocilizumab—steroid-sparing biologic

For Other Causes

• Blood pressure management—for orthostatic hypotension
• Migraine treatment—if migraine with aura
• Treatment of papilledema—if raised intracranial pressure

Risk Factor Modification

• Smoking cessation
• Blood pressure control
• Diabetes management
• Cholesterol control
• Weight management
• Regular exercise

Frequently Asked Questions

Is transient vision loss a stroke?

No, but it can be a warning of impending stroke. About 10-15% of people with transient vision loss from carotid disease will have a stroke within 90 days without treatment.

My vision came back—why do I need to see a doctor?

Because transient vision loss often indicates underlying vascular disease that puts you at risk for permanent vision loss or stroke. Finding and treating the cause can prevent these serious outcomes.

How urgently should I be evaluated?

Very urgently—ideally within 24-48 hours. If you have symptoms of giant cell arteritis (age over 50, headache, jaw pain, scalp tenderness), seek same-day evaluation.

What's the difference between this and migraine aura?

Migraine aura typically:

• Affects both eyes (when covering one eye, you still see it)
• Involves positive phenomena (shimmering, zigzag lines)
• Spreads gradually over minutes
• Is followed by headache

Transient vision loss from vascular causes typically:

• Affects one eye
• Is negative (blackout, dimming, curtain)
• Comes on suddenly
• May have no headache

Will this happen again?

Without treatment of the underlying cause, episodes may recur and could progress to permanent vision loss. Treatment significantly reduces this risk.

References