Top 14 Double Vision Causes
1. Dry Eyes
Dry eyes occur when the eyes dry out too quickly or don’t produce enough tears to keep the eyes wet. Symptoms of dry eyes include sensitivity to light, redness, and soreness. Dry eyes are a common cause of monocular double vision, or double vision in one eye.
Common causes of dry eyes include medications such as antihistamines and decongestants, medical conditions like diabetes and lupus, and the natural aging process. Dry eyes can also occur because of reduced blinking, an imbalance in tear composition, and environmental factors, including wind, smoke, and dry air.
Astigmatism is a condition in which the surface of the cornea is abnormally shaped and has two curves that contribute to blurred or double vision. Common symptoms of astigmatism include headaches, eye strain, excessive squinting, and double vision.
Many people with astigmatism are born with the condition, but others can develop it later in life. Astigmatism can also be the result of an eye injury or develop after an eye disease or surgery. People who are nearsighted or farsighted are more likely to suffer from astigmatism than those with good vision.
Cataracts are an eye condition in which the lens of the eye becomes cloudy and causes blurred, hazy, and double vision. Having cataracts is similar to looking through a fogged-up window, and it can impair the ability to see clearly in dim lighting.
Aging is the most common cause of cataracts, which tend to be more prevalent in people over the age of 40. Other risk factors for cataracts include smoking, chronic diabetes, eye trauma, and using steroid medications.
Keratoconus is a condition in which the cornea becomes thin and bulges outward like a cone to cause glares and halos at night, streaking of lights, and blurred or double vision. This eye condition can develop suddenly and quickly or gradually over several years. Many times, keratoconus develops in one eye first before affecting the other eye.
The exact cause of keratoconus is unknown, but risk factors for this condition include rubbing the eyes vigorously and having a family history of keratoconus. Certain health conditions, including asthma, hay fever, and Down syndrome, are also risk factors for keratoconus.
Pterygium, also known as surfer’s eye, is a growth that covers the white of your eye over the corner. This growth is pink, fleshy tissue shaped like a wedge. It can spread and grow toward the pupil to cause vision problems, including double vision. Pterygium might produce no symptoms or cause the affected eye to itch, burn, and feel gritty.
The exact cause of pterygium is unknown, but risk factors include excessive exposure to UV light; regular exposure to wind, smoke, sand, and pollen; and living in a sunny, warm climate.
Diabetes is a group of diseases characterized by high blood sugar levels. Type 2 diabetes is the most common type of diabetes, and it is caused by insulin resistance. Type 1 diabetes is a condition in which the pancreas produces little or no insulin, sometimes leading to dangerously high spikes in blood sugar, or hyperglycemia.
Hyperglycemia can cause fluid to leak into the lens of the eye, resulting in double vision in both eyes, or binocular double vision.
7. Graves’ Disease
Graves’ disease is an autoimmune condition that results in an overactive thyroid gland. With Graves’ disease, the body produces excess amounts of thyroid hormones to cause swelling of the neck and eyes, bulging eyes, and vertical double vision in both eyes. Eye and vision problems associated with Graves’ disease fall under a condition called Graves' ophthalmopathy.
Graves’ ophthalmopathy is caused by the buildup of carbohydrates in the soft tissue behind the eyes, which might occur because of thyroid dysfunction. While the exact cause of Graves’ disease is unknown, risk factors include having a family history of Graves’ disease, being under the age of 40, smoking, and pregnancy.
8. Brain Conditions
Health conditions that affect nerves in the brain can sometimes cause double vision, as the brain uses nerves to process visual information from the eyes. Migraine headaches, brain tumor, brain aneurysm, and stroke are some brain conditions that can cause double vision. Double vision can also be the result of pressure in the brain caused by bleeding, trauma, or infection. Treatment for brain conditions can help reverse or improve double vision.
9. Head or eye injury
A hard blow to the head or eyes may cause temporary double vision. Often, these symptoms disappear on their own as the injury heals, but some head injuries can be serious or even fatal. Eye injuries may also cause permanent damage to your vision. If you suffer a serious head or facial injury, seek medical care immediately.
10. Thyroid conditions
The thyroid is a gland located in the neck that produces essential hormones. Certain chronic health conditions can cause thyroid dysfunction. Hormonal imbalances caused by thyroid dysfunction can trigger vision changes or double vision.
11. Stroke or aneurysm
A stroke or aneurysm can put pressure on your optic nerves. In some cases, a stroke or aneurysm can also affect blood flow to your eyes. If your eyes aren't receiving enough blood, you may experience vision changes.
Vision problems can occur before, during, or after a stroke or aneurysm. Tell your doctor about any sudden vision changes. Seek medical care right away if you have vision changes accompanied by dizziness, headache, or confusion.
Tumors in the brain or eye area are rare, but they can sometimes be responsible for double vision. Tumors that develop behind your eyes may cause damage to the optic nerve. Some tumors can also affect your eye muscles and prevent you from focusing your eyes.
13. Eye dysfunction
If you have trouble focusing your eyes, you might have a condition known as convergence insufficiency. This condition may prevent the muscles in your eyes from lining up correctly. Convergence insufficiency can trigger a wide range of vision problems, including double vision.
14. Eye infections
Eye infections are a common cause of vision changes, particularly among children. Symptoms of eye infections include itching, pus discharge, or redness around the eyes. These infections are often mild, but they can sometimes cause permanent eye damage. They can also be highly contagious. Report any symptoms of infection to your doctor right away.
Possible Health Conditions Related to Double Vision
Astigmatism is an abnormal curvature of the cornea, a structure located inside your eye. Problems with your cornea can cause double vision, blurry vision, eye strain, and headaches. Most cases of astigmatism can be corrected with glasses or contact lenses. In some cases, eye surgery may be necessary.
Having diabetes puts you at risk for serious vision problems, including permanent eye damage. Regular high spikes in blood sugar can damage soft tissue in the eyes and cause double vision. If you have diabetes, see your eye doctor often for exams and vision screenings. Report any vision changes to your medical team right away.
3. Multiple sclerosis (MS)
MS is an autoimmune disease that can damage the nerve fibers in the body. This damage can prevent your body from sending signals from your eyes to your brain. Nerve damage caused by MS may be responsible for some cases of blurred or double vision.
Cataracts develop when the lens inside your eye becomes clouded. This clouding can cause light sensitivity and blurred or double vision. Cataracts are very common, especially among older adults. Cataract surgery can clear up a clouded lens and improve your vision.
Epilepsy, or seizure disorder, affects the nerves in your brain. People with epilepsy can experience unpredictable seizures. In some cases, these seizures may affect their vision. Many people with epilepsy report sudden vision changes before or after a seizure.
A concussion can develop after a hard blow to the head. Concussions often cause serious injury to the brain and may interfere with normal brain function. Many people who experience concussions make a full recovery, but some experience long-term complications, including vision changes.
7. Dry eye
People with dry eyes may not produce enough tears to lubricate the eyes. Their tears can also dry out too quickly, leaving their eyes inflamed and sore and causing double vision. If you have dry eyes, you may notice that your eyes often feel itchy, sandy, or irritated. Prescription eye drops can help relieve your symptoms.
8. Myasthenia gravis
Myasthenia gravis is a health condition that can cause damage to the nerves in your body. Nerve damage caused by myasthenia gravis can affect your vision. People with this condition often report blurred or double vision, difficulty swallowing, muscle weakness, and facial drooping.
This contagious virus causes open sores on the mouth, genitalia, and other parts of the body (including the eyes), sometimes causing double vision.
10. Grave's Disease
This autoimmune condition involving an overactive thyroid can affect vision and cause vertical double vision.
11. Guillain-Barre syndrome
When this progressive neurological disorder attacks and weakens nerves in the eye, it causes double vision.
Questions Your Doctor May Ask About Double Vision
- When did you start experiencing double vision?
- Have you recently fallen, suffered a blow to the head, or been unconscious?
- Is your double vision worse when you’re tired?
- Are there other symptoms that accompany your double vision?
- Do you tend to tilt your head to one side?
- Do you have double vision in one or both eyes?
- Are the double images vertical or horizontal?
- Are there any factors that worsen or relieve your double vision?
- Do you suffer from any other medical conditions?
Double Vision May Also be Known as
- Monocular diplopia
- Binocular diplopia
- Blurred vision
- Monocular double vision
- Binocular double vision
- National Library of Medicine. Dry eye syndrome. https://medlineplus.gov/ency/article/000426.htm
- National Library of Medicine. Management of diplopia. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5710033/
- National Eye Institute. Facts About Dry Eye. https://nei.nih.gov/health/dryeye/dryeye
- National Eye Institute. Facts About Astigmatism. https://nei.nih.gov/health/errors/astigmatism
- National Eye Institute. Common Vision Problems. https://nei.nih.gov/healthyeyes/problems
- National Eye Institute. Cataracts. https://nei.nih.gov/eyedata/cataract
- National Library of Medicine. Keratoconus. https://ghr.nlm.nih.gov/condition/keratoconus
- National Library of Medicine. Keratoconus: epidemiology, risk factors and diagnosis. https://www.ncbi.nlm.nih.gov/pubmed/16804819
- National Center for Advancing Translational Sciences. Pterygium of the conjunctiva and cornea. https://rarediseases.info.nih.gov/diseases/4569/pterygium-of-the-conjunctiva-and-cornea
- National Institute of Diabetes and Digestive and Kidney Diseases. Type 2 Diabetes. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/type-2-diabetes
- National Library of Medicine. Ocular complications of diabetes mellitus. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4317321/
- National Library of Medicine. Double vision is a major manifestation in moderate to severe Graves' orbitopathy, but it correlates negatively with inflammatory signs and proptosis. https://www.ncbi.nlm.nih.gov/pubmed/25695893
- Harvard Health Publishing. Graves' Eye Disease (Graves' Ophthalmopathy). https://www.health.harvard.edu/diseases-and-conditions/graves-eye-disease-graves-ophthalmopathy
- National Library of Medicine. Understanding vision and the brain. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5365039/
- National Library of Medicine. Ocular herpes simplex. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2907955/
- National Institute of Neurological Disorders and Stroke. Myasthenia Gravis Fact Sheet. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Myasthenia-Gravis-Fact-Sheet
- National Library of Medicine. Multiple Sclerosis. https://medlineplus.gov/multiplesclerosis.html
- National Institute of Neurological Disorders and Stroke. Guillain-Barré Syndrome Fact Sheet. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Guillain-Barr%C3%A9-Syndrome-Fact-Sheet
- Medical News Today. Why am I seeing double? https://www.medicalnewstoday.com/articles/170634.php
- American Family Physician. Concussion. https://www.aafp.org/afp/2012/0115/p137.html
- American Stroke Association. Learn more stroke warning signs and symptoms. https://www.strokeassociation.org/en/about-stroke/stroke-symptoms/learn-more-stroke-warning-signs-and-symptoms
- All About Vision. Eye infections: Bacterial, fungal and viral. https://www.allaboutvision.com/conditions/eye-infections.htm
- American Optometric Association. Astigmatism. https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/astigmatism
- National Eye Institute. Facts about diabetic eye disease. https://nei.nih.gov/health/diabetic/retinopathy
- Mayo Clinic. Dry eyes. https://www.mayoclinic.org/diseases-conditions/dry-eyes/symptoms-causes/syc-20371863
- National Institute of Neurological Disorders and Stroke. Myasthenia gravis fact sheet. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Myasthenia-Gravis-Fact-Sheet