Double vision or what is medically referred to as diplopia is a perception of two images of a single object. The images are seen adjacent or overlapping each other and could be horizontally or vertically placed. It can occur to one or both the eyes and can cause problems of balance, vision, coordination, movement and reading. This is a serious condition, which should be tested and treated immediately, even if the problem only occurs temporarily.

Typically, there are two types of double visions:

• Monocular: This is double vision in one eye. Monocular is usually due to an underlying eye problem. This is a less common type of double vision problem.
• Binocular: This type of diplopia affects both the eyes. This is typically caused by an underlying issue within the brain or the eye nerves. This is a very common type of double vision problem.

 

What are the symptoms of double vision?

The primary symptom of double vision is the perception of two images of a single object. In many cases, a double vision problem might not have any other symptoms. However, for cases where a person experiences symptoms, they may be related to the underlying cause of the problem. These could include:

• Problems with eye alignment, such as cross-eye, wandering eye, etc.
• Pain while moving the eye from side-to-side or up and down.
• Severe or mild pain in and around the eyes, including areas such as temples and eyebrows.
• Extreme headache with no definitive cause.
• Nausea.
• Dryness in the eyes, causing itching and irritation.
• Falling eyelids and tired eyes.

 

What are the causes of double vision?

There can be many double vision causes. The exact double vision cause is dependent on the type of problem.

Reasons for monocular double vision

Monocular diplopia (double vision in one eye) can be a result of any of the following issues:

• Astigmatism: This condition occurs due to an abnormal curve on the cornea, which obstructs the vision.
• Keratoconus: This is gradual thinning of the cornea, which eventually causes the cornea to become cone-shaped. This condition worsens with age.
• Pterygium: This is the thickening of the conjunctiva, which ultimately impacts the cornea.
• Cataracts: Most often caused due to age, this condition makes the cornea less transparent.
• Dry eye: In this problem, the eyes are less hydrated, do not produce enough tears and dry out too fast. It can be caused due to absence of protective lenses while using laptops, TVs, mobile phones, etc. or even unprotected exposure to sun rays, etc. 
• A displaced lens: Often caused due to a trauma, a displaced lens occurs when the ligaments acting as holders break down. 
• Retinal issues: These include unclear retinal surface, mass or swelling, etc.

Reasons for binocular double vision

This is caused by the misalignment of the eyes. Some of the causes of binocular double vision (double vision in both eyes) include:

• Strabismus: This is more common in children, where the eyes look faintly in diverse directions. This can be because of weak, paralyzed, or overactive muscles, as well as due to restriction of muscle movement or other related issues.
• Nerve damage: Nerves of the muscles surrounding the eyeballs can be impacted or injured due to brain damage. The brain damage can be a result of a particular infection, multiple sclerosis, trauma, brain tumour, stroke, etc. Moreover, a tumour in the eye can also damage the nerves.
• Diabetes: Categorized by high glucose levels in the body, diabetes can affect the blood vessels and nerves surrounding the eyeballs or supplying the retina.
• Myasthenia gravis: A neuromuscular issue which can cause the eye muscles to become too weak.
• Trauma: Facial trauma can impact the eye muscles and often lead to a fracture of the eye socket bones.
• Thyroid dysfunction: Alterations in the thyroid function (overactive thyroid) can impact the muscles of the eyes, causing thickening and swelling. 

 

What is the treatment of double vision?

The treatment of diplopia depends on the underlying issue and the type of double vision. In both types – monocular and binocular, the below treatment methods can prove effective to resolve the issue. But in some cases, surgical intervention may be required.

The types of treatment can include:

• Wearing corrective glasses 
• Opting for preventive lenses, such as computer glasses, anti-glare lens, reflective glasses, blue-light protection lenses, UV protected lenses, to avoid straining the eyes and keeping them from drying out.
• Undertaking eye exercises such as smooth convergence, jump convergence, etc.
• Opting for opaque contact lenses
• Getting relaxant injections for the eye muscles
• Using an eye patch
• Getting the correction through surgery

 

Should you visit an optician?

Yes, a person facing a double vision problem (even if temporary) should visit an optician. The optician will conduct comprehensive eye exams to relate the symptoms and identify a possible cause. The optician will also study the ophthalmologist’s report and based on the issue, will give a prescriptive lens to solve the diplopia problem. For initial cases, visiting the optician timely can help prevent further damage or intensification of the problem. 

 

FAQs

What causes double vision that comes and goes?

The problem of double vision can be caused due to multiple underlying reasons such as dry eye, cataracts, weakness or damage of eye muscles, facial trauma, overactive thyroid, diabetes, strabismus, etc. The exact cause will need to be determined with an analysis.

How long does double vision last after strabismus surgery?

Post a strabismus surgery, the brain takes several weeks to adjust to the new position and improve vision. Eye exercises and therapies are also recommended to expedite the recovery process.

What causes sudden double vision?

Sudden diplopia can be temporary due to alcohol, drugs or other medications. Moreover, head injuries, concussions, etc. can also cause sudden double vision. The recurring diplopia problem may be due to multiple underlying causes such as dry eyes, cataracts, overactive thyroid, diabetes, strabismus, etc.

Is double vision a sign of a stroke?

Yes, stroke can be one of the double vision causes. It can also cause blurred vision issues or even loss of sight in one eye. However, it is not very common.