Contact Lens Care
About Contact Lenses
Children's Eye Health
Lenses & Lifestyle
Prescriptions & Eye Tests
What is double vision (diplopia)?
Medically referred to as diplopia, double vision is seeing double images of a single object. The photos may be side by side, on top of one another, or a mixture of both. On some occasions, you may even see more than two images of the same object.
Depending on the cause, double vision can either be a temporary issue or a long-term condition. Seeing in double vision may cause you to become anxious, dizzy, disoriented and confused. You may even experience the same symptoms when you close your eyes.
As with all other medical conditions, it is essential to inform the DVLA if you regularly suffer from diplopia. Failure to disclose diplopia or any other medical condition could result in a £1000 fine or prosecution if you were to be involved in an accident. You can report diplopia  to the DVLA by clicking here.
What causes sudden double vision?
A head injury, tumour, swelling or aneurysm in the brain can cause sudden double vision, and will usually continue until the problem has gone.
What is double vision a symptom of?
We often take for granted the complex process that occurs for our eyes to be able to function smoothly. Our double vision can affect either one eye (monocular diplopia) or both (binocular diplopia), which usually dictates which kind of treatment you’ll require.
Temporary moments of double vision can be caused by a blow to the head, drinking too much alcohol or extreme tiredness. Double vision resulting from this is short term and usually disappears quickly.
Several other conditions can cause long-term double vision.
Causes of binocular double vision
A squint (strabismus is the medical term) refers to a condition in which your eyes point in different directions. Squinting happens when the muscles controlling your eyes are either too strong or too weak. If the eye muscles are too strong, they cannot move smoothly. If they are too weak, they are unable to move. Not all squints cause double vision, and they are particularly common in young children.
After an eye examination, you'll see a neurologist or neurosurgeon for more comprehensive tests and diagnosis. Brain injuries can lead to more health complications and may cause diplopia to be a reoccurring issue.
Cranial nerve palsies
Paralysis or loss of coordination of the muscles that control how the eyes work together can also cause double vision. These can both be a result of cranial nerve palsy. Many things cause cranial nerve palsies, such as:
- A Tumour
- High blood pressure
- A head injury
- A brain aneurysm
- Blockage in an artery
A doctor will usually look at each underlying issue and look at ways of dealing with the condition upon diagnosis.
Graves disease causes an overactive thyroid which can lead to a range of vision problems including binocular diplopia. Binocular diplopia caused by graves disease is due to the swelling of the muscles which control eye movement.
Damage to the nerves controlling extraocular muscles can be caused by multiple sclerosis which can then lead to binocular double vision.
Causes of monocular double vision
Monocular double vision is double vision in one eye and is a less common condition.
Abnormalities of the eye’s lens due to cataracts, or the retina due to macular degeneration, as well as refractive surgeries to correct these conditions, can cause double vision. Vision usually goes back to normal after a patient has recovered.
Dry eyes, particularly more severe conditions such as Sjogren’s syndrome, can cause ghost images. Eye drops can help this by reintroducing moisture into the eyes if they are not producing enough tears.
Usually caused by astigmatism, the irregular shape of the cornea affects how light passes through the eye, resulting in images appearing blurry. People with minor astigmatism may not even notice a blurriness in their vision, whereas people with more pronounced astigmatism will need corrective lenses.
Temporary double vision
Alcohol, head injuries, benzodiazepines, opioids and certain medications for seizures or epilepsy can cause temporary double vision as can fatigue or having strained eyes.
Swelling in the eyelid
Swelling can press on the front of the eye and result in seeing a double image.
Does double vision go away?
In some cases, double vision can go away on its own; however, if it stays with you for more than a couple of hours, you should contact your doctor immediately.
If your double vision disappears when you cover one eye, you could have a damaged cornea in the other eye.
How is double vision treated?
As most double vision is the result of underlying issues, once treated, your sight will usually return to its normal state. Before prescribing treatment for double vision, your eye care specialist will ask you whether its monocular or binocular. The procedure will then depend on the cause.
Treatments for monocular double vision
Double vision caused by dry eyes can be treated by regularly using eye drops. You can purchase standard eye drops such as Blink Intensive Care eye drops from our site. More intense dry eye may require eye drops prescribed by an optician or GP.
Double vision caused by corneal irregularities (usually as a result of astigmatism) requires a corrective lens to treat. A corrective lens can be either prescription glasses or toric contact lenses.
Double vision from a brain or head injury usually clears up quickly after the injury. Depending on the damage, in some cases, the double vision may be a reoccurring issue.
Double vision caused by abnormalities such as cataracts may result in double vision immediately after cataracts surgery but usually clears up quickly.
Treatments for binocular double vision
There are various treatments for binocular double vision, depending on what's causing it. These include:
- Eye exercises-this can help if strained or weakened muscles cause your double vision. By strengthening the eye muscles with eye exercises, your double vision should resolve
- Wearing an eye patch-this can be used as a short term solution before a permanent solution
- Contact lenses or glasses-they can help to adjust your sight and correct the problem
- Surgery-this can correct the positioning of the eye's muscles
- Botox injections-injecting the eye muscles with botulinum toxin can help to correct double vision by re-balancing the muscles of the eyes
Your doctor will note down your symptoms and look for other problems affecting vision by carrying out some tests. Determining whether you have binocular or monocular double vision is pretty simple; however, finding the cause is usually more complicated and may require various tests.
A physical exam might involve:
- Blood tests
- A dilated eye exam
- eye movement tests
- blood sugar tests
- A CT scan or MRI
 GOV.UK. (2019). Diplopia (double vision) and driving. [online] Available at: https://www.gov.uk/diplopia-and-driving [Accessed 21 May 2019]