Diplopia (Double Vision): What Causes It, How It's Classified, and When It's an Emergency
Updated: 4 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Diplopia is double vision, seeing two images of a single object, usually a temporary issue from cataracts, dry eye or an outdated prescription. Monocular diplopia is usually less serious than binocular. See an eye specialist right away, and go to the emergency room if it persists for hours or comes with pain, weakness, slurred speech or confusion.
What the research says
Most emergency visits for double vision involve binocular diplopia, and many need urgent treatment. In a retrospective study of 788 patients admitted for diplopia to two French university hospital emergency departments, 95% had binocular diplopia; the most common causes were microangiopathies (33%), strokes (19%), and myasthenia gravis (5%). Imaging was done in 90% of patients, 42% needed urgent treatment of the cause, and 31% were hospitalized (PubMed: Occelli et al., Am J Emerg Med, 2025).
Sudden eye-movement double vision isn't always "just" a blocked small vessel. In a prospective multicenter study of 109 patients aged 50 or older with acute isolated third, fourth, or sixth cranial nerve palsy, MRI and clinical assessment found a cause other than presumed microvascular ischemia in 16.5% (95% CI 10.7%–24.6%), including neoplasm, giant cell arteritis, and brainstem infarction (PubMed: Tamhankar et al., Ophthalmology, 2013).
Ocular motor nerve palsy is linked to a higher later risk of stroke. In a Korean national cohort comparing people with third, fourth, or sixth cranial nerve palsy with matched controls, the palsy group had a higher risk of subsequent stroke (hazard ratio 1.23, 95% CI 1.08–1.39), and the risk was highest for people in their 30s (hazard ratio 8.91, 95% CI 1.63–48.66) (PubMed: Choi et al., J Am Heart Assoc, 2024).
What Is Diplopia?
Diplopia is the medical term for double vision — the experience of seeing two images of a single object you're looking at. It can feel alarming, and for good reason: it can decrease your depth perception, making everyday activities like driving or walking more difficult and potentially unsafe.
The reassuring news is that double vision is usually a temporary issue. However, it can also be a sign of more serious health conditions. That's why the standard advice is straightforward: visit a healthcare provider or eye care specialist right away if you start seeing double.
Key fact | Detail |
Definition | Seeing two images of a single object |
Typical course | Usually temporary |
Main concern | Can decrease depth perception, affecting driving and walking |
First step | See a healthcare provider or eye care specialist right away |
What are the types of diplopia (double vision)?
An eye care specialist will first classify your double vision by whether it persists when one eye is closed. That single check separates the most common, least serious form from the kind that tends to be more serious.
Monocular diplopia happens when you have double vision even when you close or cover one of your eyes. It may look like there are shadows in your vision. Monocular diplopia is the most common type, and it's usually the least serious.
Binocular diplopia is double vision that occurs only when both of your eyes are open. It goes away if you cover or close one eye. Eyes that are out of alignment, or health conditions that affect your vision, are common causes. Binocular diplopia is usually more serious.
Type | What happens | When it disappears | Severity |
Monocular diplopia | Double vision persists with one eye closed; may look like shadows | Doesn't disappear when one eye is covered | Most common; usually least serious |
Binocular diplopia | Double vision only with both eyes open | Goes away when one eye is covered or closed | Usually more serious |
Vertical and Horizontal Diplopia
Your eye care specialist might also classify diplopia by where the doubled images appear in your vision. Vertical diplopia means you're seeing extra images above or below your true vision. Horizontal diplopia is seeing doubled images side to side.
How Common Is Double Vision?
Diplopia is very common. Experts estimate that more than 800,000 people a year in the U.S. visit an eye care specialist because they're having some form of double vision. It's also one of the most common reasons people go to the emergency room, with around 50,000 people every year going to the ER because they have double vision.
Frequency measure | Estimate |
Annual U.S. eye care specialist visits for double vision | More than 800,000 |
Annual U.S. emergency room visits for double vision | Around 50,000 |
What are the symptoms of diplopia (double vision)?
Beyond seeing double, you might experience other symptoms if you have diplopia. These associated symptoms can include a headache, nausea (upset stomach or feeling sick), dizziness, or eye pain — including pain when you move your eyes.
Associated symptom | Description |
Headache | Pain in or around the head |
Nausea | Upset stomach or feeling sick |
Dizziness | Unsteadiness or a spinning sensation |
Eye pain | Pain including when you move your eyes |
What Causes Double Vision?
Lots of eye problems can cause double vision. In general, anything that affects your brain, your eyes, or the nerves and muscles that control them can lead to diplopia.
Common eye-related causes include refractive errors such as astigmatism, nearsightedness (myopia), and farsightedness (hyperopia), as well as poorly fitting glasses or contacts, cataracts, dry eye syndrome, iris abnormalities, and keratoconus. Other causes include migraines, cranial nerve issues, proptosis (bulging eyes), and head injuries.
Category | Causes |
Refractive errors | Astigmatism, nearsightedness (myopia), farsightedness (hyperopia) |
Eyewear issues | Poorly fitting glasses or contacts |
Eye conditions | Cataracts, dry eye syndrome, iris abnormalities, keratoconus |
Neurological and other | Migraines, cranial nerve issues, proptosis (bulging eyes), head injuries |
What are the risk factors for diplopia (double vision)?
Anyone can experience double vision, but it's most common in adults older than 60. Having certain neurological or other health conditions can also increase your risk.
Risk factor | Why it matters |
Age over 60 | Most common age group for double vision |
Myasthenia gravis | Neuromuscular condition affecting eye muscles |
Vertigo | Balance-related condition linked to vision disturbance |
Brain aneurysms | Vascular issue that can affect cranial nerves |
Strokes | Brain events that disrupt eye movement control |
Diabetes | Includes diabetes-related retinopathy |
Vitamin B1 (thiamine) deficiency | Nutritional deficiency affecting nerves |
Thyroid disease | Can affect eye muscles and alignment |
Multiple sclerosis (MS) | Neurological condition affecting nerve signals |
How Do Providers Diagnose Diplopia?
An eye care specialist will diagnose double vision and what's causing it. The process starts with an eye exam and a visual acuity test to check your vision.
If you have monocular diplopia, you likely won't need additional tests. If you have binocular diplopia, you might need an MRI, a CT scan, or blood tests. These tests help your eye care specialist see all the parts of your eyes and the area around them to identify issues with your bones, muscles, brain, or spine that might cause double vision.
Diagnostic step | Purpose |
Eye exam | Overall assessment of eye health |
Visual acuity test | Checks how clearly you can see |
MRI | Views the eyes, brain, and surrounding structures |
CT scan | Views the eyes, brain, and surrounding structures |
Blood tests | Checks for underlying conditions affecting the eyes, nerves, or muscles |
How Is Double Vision Treated?
Which treatments you'll need depends on what's causing diplopia. Your eye care specialist or healthcare provider will treat the cause.
Some people only need new (or adjusted) glasses or contacts. You might have to cover one eye for a while or wear a special contact lens to help your eyes regain their usual sight. Your eye care specialist will walk you through how to manage your symptoms, including getting rid of the diplopia.
Treatment approach | When it's used |
New or adjusted glasses or contacts | When refraction or poorly fitting eyewear is the cause |
Covering one eye temporarily | To manage symptoms while the cause is treated |
Special contact lens | To help the eyes regain their usual sight |
Surgery | To correct issues in the eye, such as cataract removal |
How Soon After Treatment Will I Feel Better?
It depends on what's causing the diplopia. Some cases of double vision go away on their own, while others won't get better until your eye care specialist treats the cause. If you need surgery to correct the issues in your eye — like removing cataracts — you might need a few weeks to feel better.
What Can I Expect If I Have Diplopia?
Double vision is usually a short-term issue. You shouldn't drive or do anything else that could hurt yourself or others while your vision is impaired. Depending on what's causing the diplopia, you might need to make some adjustments to your daily routine.
When Should I Worry About Double Vision?
Double vision is always concerning, but you shouldn't assume the worst. Most cases are temporary — in fact, the diplopia might go away on its own. But you should still get your eyes checked if you experience double vision.
If you have double vision more than once, or if it comes and goes, you could have transient (intermittent) diplopia. Even if your double vision clears up on its own, you should see an eye care specialist or healthcare provider.
How Can I Prevent Diplopia?
Diplopia cannot be prevented specifically, but caring for your eyes and seeing an eye care specialist regularly helps catch problems early. But taking good care of your eyes and seeing an eye care specialist regularly are the best ways to catch issues as soon as possible.
Eye health habit | Recommendation |
Smoking | Don't smoke |
Screen time | Give your eyes a break from electronic screens throughout the day |
Eye protection | Wear appropriate protective glasses or goggles for work, sports, or hobbies |
Eye exams | Schedule an exam every one to two years, or as often as your eye care specialist recommends |
How can people live well with diplopia (double vision)?
Tell your eye care specialist about any changes in your eyes or vision. If you wear glasses or contacts, have your eyes examined regularly so your provider can adjust your prescription as often as necessary. Visit your eye care specialist as soon as you notice any changes in your vision. Whether it's something as simple as needing new glasses or a more serious condition, don't wait for symptoms to get worse before having your eyes checked.
When Should I Go to the Emergency Room?
Go to the emergency room if you're experiencing double vision that doesn't go away in a few hours, or if you have any of the following symptoms:
Eye pain
Dizziness
Muscle weakness
Slurred speech
Confusion
Diplopia can be the first sign of serious brain issues like strokes. Also, go to the emergency room if you experience a trauma like a car accident or fall and have worse or double vision after it.
Red flag | Action |
Double vision lasting more than a few hours | Go to the emergency room |
Double vision with eye pain | Go to the emergency room |
Double vision with dizziness | Go to the emergency room |
Double vision with muscle weakness | Go to the emergency room |
Double vision with slurred speech | Go to the emergency room |
Double vision with confusion | Go to the emergency room |
Double vision after a trauma (car accident, fall) | Go to the emergency room |
Key Takeaways
Diplopia is double vision — seeing two images of a single object. It's very common, usually temporary, and most often caused by eye conditions. It's classified as monocular (persists with one eye closed, usually least serious) or binocular (goes away with one eye closed, usually more serious). See an eye care specialist right away when it starts, don't drive while your vision is impaired, and treat double vision that lasts more than a few hours — or comes with pain, dizziness, weakness, slurred speech, or confusion — as an emergency.
Take the Next Step
Take care of your vision. If you're experiencing double vision, book an eye exam today and don't wait for symptoms to get worse. Catching the cause early protects your sight and your safety.
Related reading: cataracts, migraine headaches, stroke
Frequently Asked Questions
1. What is diplopia?
Diplopia is the medical term for double vision — seeing two images of a single object you're looking at. It's usually a temporary issue but can signal more serious health conditions, so you should see a healthcare provider or eye care specialist right away when it starts.
2. What is the difference between monocular and binocular diplopia?
Monocular diplopia persists even when you close or cover one eye and may look like shadows in your vision — it's the most common and usually least serious type. Binocular diplopia only happens when both eyes are open and goes away if you cover one eye — it's usually more serious.
3. Is double vision a sign of something serious?
Double vision can be. Double vision is usually a temporary issue, but it can signal more serious health conditions, including strokes. If it doesn't go away within a few hours or comes with eye pain, dizziness, muscle weakness, slurred speech, or confusion, go to the emergency room.
4. How common is diplopia?
Very common. More than 800,000 people a year in the U.S. visit an eye care specialist for double vision, and around 50,000 go to the emergency room for it annually. It's one of the most common reasons people visit the ER.
5. Who is most at risk for double vision?
Anyone can experience double vision, but it's most common in adults older than 60. Conditions like myasthenia gravis, vertigo, brain aneurysms, strokes, diabetes, vitamin B1 deficiency, thyroid disease, and multiple sclerosis also increase risk.
6. What causes monocular diplopia?
Monocular diplopia is usually caused by eye conditions such as astigmatism, nearsightedness, farsightedness, poorly fitting glasses or contacts, cataracts, dry eye syndrome, iris abnormalities, or keratoconus.
7. Why am I seeing double all of a sudden?
You'll usually notice diplopia suddenly, even if the underlying issue develops over time. Sudden double vision can be a red flag of serious health conditions, though it's usually temporary. See an eye care specialist as soon as you notice the change.
8. Can double vision be cured?
It depends on the cause. Some cases go away on their own, while others improve only after your provider treats the underlying cause — such as new glasses, cataract surgery, or managing a neurological condition. Recovery can take a few weeks if surgery is involved.
9. What should I avoid doing while I have double vision?
Don't drive or do anything else that could hurt yourself or others while your vision is impaired. Your depth perception can be reduced, making driving and walking more difficult and potentially unsafe.
10. What is transient (intermittent) diplopia?
Transient or intermittent diplopia is double vision that happens more than once, or comes and goes. Even if your double vision clears up on its own, you should still see an eye care specialist or healthcare provider.
11. How can I protect my eyes and reduce my risk of diplopia?
There's nothing that specifically prevents double vision, but you can support eye health by not smoking, giving your eyes regular breaks from screens, wearing protective eyewear during work and sports, and scheduling an eye exam every one to two years.
References
Cleveland Clinic. Diplopia (Double Vision). Cleveland Clinic. Aug. 6, 2024. https://my.clevelandclinic.org/health/diseases/22203-diplopia-double-vision
Occelli C, Coffin V, Raynaud O, et al. Presentation, management and outcomes of patients with diplopia in the emergency department. Am J Emerg Med. 2025;96:170-175. doi:10.1016/j.ajem.2025.06.024. PMID: 40580880.
Tamhankar MA, Biousse V, Ying GS, et al. Isolated third, fourth, and sixth cranial nerve palsies from presumed microvascular versus other causes: a prospective study. Ophthalmology. 2013;120(11):2264-2269. doi:10.1016/j.ophtha.2013.04.009. PMID: 23747163.
Choi DD, Cheon DY, Park KA, et al. Age-related risk of stroke following ocular motor cranial nerve palsy. J Am Heart Assoc. 2024;13(12):e033437. doi:10.1161/JAHA.123.033437. PMID: 38879451.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
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