Double vision, or diplopia, is a condition where a person perceives two images of a single object instead of one. This problem significantly affects visual quality and can stem from various causes, ranging from simple eye disorders to neurological diseases. Double vision can be temporary or permanent, depending on the underlying health issues.
What is Double Vision (Diplopia)?
Diplopia is the condition where a person sees two images of a single object. In this situation, double images may appear overlapping, side by side, or crossed. Altering the head position or closing one eye might change or eliminate the double vision effect. Double vision can be classified as;
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Monocular (double vision in one eye)
Monocular diplopia often refers to vision difficulties in one eye. It describes the persistence of double vision even when one eye is closed. Monocular diplopia may be due to issues in the eye's optical system or problems related to the retina.
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Binocular (double vision in both eyes)
Binocular diplopia, which occurs when objects appear double when viewed with both eyes, is caused by damage in the vision axes that should normally be parallel. In this condition, a person can see clearly with one eye but experiences double vision when both eyes are open.
What Are the Common Causes of Double Vision?
Double vision can be a symptom of various health issues. Some common causes of this condition include:
Causes of Binocular Double Vision
Double vision resulting from the impairment of muscles and nerves that enable coordinated eye movement can arise from different causes. Some common reasons include:
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Strabismus: Strabismus can begin in childhood or develop in adulthood. Due to the inability of the eyes to look parallel, two different images form, which the brain cannot integrate.
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Eye Muscle Paralysis: Paralyses affecting the eye muscles can also cause double vision issues. Particularly, 3rd, 4th, and 6th nerve paralyses affect eye muscles. Systemic diseases like diabetes and hypertension are frequent causes of such paralyses.
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Graves' Disease: In Graves' disease, where the thyroid gland is overactive, swelling and inflammation can occur in eye muscles. This condition may restrict eye movements and lead to double vision problems.
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Orbital Tumors: Orbital tumors or mass formations can compress the eyeball, resulting in movement disorders and consequently causing double vision problems.
Due to these causes, individuals experiencing double vision should undergo a detailed eye examination by a specialist ophthalmologist.
Causes of Monocular Double Vision
Double vision that persists with one eye closed typically originates from structural abnormalities in the eye. Primary causes include astigmatism, cataracts, corneal problems, and dry eyes.
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Astigmatism: Astigmatism is caused by the curvature of the cornea preventing proper refraction of light. In this situation, a person perceives blurry or double images.
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Cataract: Cataracts cause a dispersion of vision due to lens clouding. Individuals with cataracts perceive blurred images that are difficult to focus on instead of clear vision.
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Corneal Problems: Corneal problems can also be the reason for double vision when one eye is closed. Diseases like keratoconus involving thinning or deformation of the cornea can result in unclear images.
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Dry Eyes: Insufficient moisture on the eye surface makes clear and sharp vision difficult and can cause double vision.
Monocular diplopia generally arises from eye-specific issues and is distinct from neurological problems. If double vision persists when viewing with a single eye, underlying eye health issues should be addressed.
Causes of Double Vision at a Distance
If double vision occurs only when looking at distant objects, it is generally due to the dysfunction of eye muscles or the prominence of refractive errors.
Occasional Double Vision
Double vision is not always constant. Fatigue, stress, low blood sugar, migraine attacks, or temporary muscle weakness can lead to periodic diplopia in some individuals.
What Are the Symptoms of Double Vision?
Alongside double vision, the following symptoms may also be observed:
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Images may be perceived side by side, stacked on top of each other, or crossed. For example, a single object may appear in multiple ways, or a sensation of it being in two different places may occur.
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Dizziness and balance loss are also common symptoms. Balance issues experienced alongside double vision can reduce the quality of life.
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Limitations in eye movements accompany double vision as a symptom. Involuntary deviation of the eyes or difficulty focusing can be observed.
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Drooping of the eyelid (ptosis) may occur. The eyelid may be lower than it should be, affecting vision.
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Head and eye pain are frequently encountered complaints. An increase in these types of pain during double vision is a common situation and can intensify discomfort.
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Blurred or shadowed vision is also associated with double vision. The lack of clarity or shadowed perception can complicate interaction with one's environment.
An immediate medical evaluation is needed if symptoms suddenly appear. Early diagnosis and treatment can help determine the fundamental issues related to double vision and contribute to preventing serious complications.
How is Diplopia Diagnosed?
To diagnose diplopia, initial steps involve querying the symptoms and any previous eye disorders.
Following a physical examination, various tests may be requested to confirm the diplopia diagnosis. CT scan, blood tests, and MRI may be included in these tests.
Diagnostic stages:
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Evaluation of Eye Muscles: Mobility limitations of the eye are checked.
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Fundoscopic Examination: The retina, optic nerve, and vascular structures are examined.
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Determining Refractive Errors: Issues like astigmatism or hyperopia are identified.
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Cornea and Lens Examination: Cataracts or keratoconus are investigated.
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Neurological Assessment: If nerve paralysis and brain disorders are suspected, imaging methods like MRI and CT are requested.
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Thyroid Function Tests: Investigating Graves' disease.
What Are the Treatment Methods for Double Vision?
The treatment of double vision is shaped by various methods based on the underlying cause. Early diagnosis and correct treatment methods are crucial in preventing permanent visual impairments.
- Use of Glasses and Prismatic Lenses: Glasses and prismatic lenses are preference options for treating diplopia due to mild strabismus or refractive errors. Prismatic lenses help in reducing the double vision issue by converging images at a single point.
- Eye Exercises: Eye exercises can also be effective in treating double vision. Through specialized exercise programs, eye muscles are strengthened, coordination is improved, and symptoms are alleviated.
- Tear Drops: In cases of double vision induced by dry eyes, artificial tear drops may be used. Drops help in moisturizing the eye surface, providing relief and reducing the double vision sensation.
- Cataract Surgery: Cataract surgery is a frequently chosen treatment method for double vision resulting from lens clouding. Surgical intervention removes the cloudiness and restores clarity.
- Treatment for Nerve Paralysis: Nerve paralysis cases related to diabetes, hypertension, or nerve compression are monitored with medication therapy. Early intervention supports nerve functions, bringing double vision symptoms under control.
- Thyroid Treatment: Endocrinological treatment can be applied to muscle problems associated with thyroid diseases. Hormonal regulation in diseases like Graves’ disease helps in controlling muscle problems, reducing double vision effects.
- Surgical Intervention: Operations aimed at correcting the positioning of eye muscles can address and resolve double vision problems by aligning the eyes.
Early diagnosis enhances treatment success and can decrease the risk of permanent visual impairments.
Frequently Asked Questions
What causes occasional double vision?
Occasional double vision can occur due to eye strain, digital screen use, lack of sleep, or low blood sugar. Additionally, migraine attacks, temporary eye muscle weakness, or neurological disorders may also cause it. Continued symptoms warrant an eye examination.
Can diplopia occur in children?
Yes, diplopia can occur in children. The common cause of double vision in childhood is strabismus, noticeable at early ages. Congenital problems or traumas affecting the eye muscles can also lead to double vision in children.
What conditions cause double vision at night?
Nighttime double vision is observed in conditions like cataracts, which cause light scattering due to lens malformation. Corneal diseases, astigmatism, or conditions affecting the retina’s light sensitivity can impair nighttime vision. Glaucoma and diabetes-related retinal diseases may also intensify night complaints.
What could be the indication of double vision at a distance?
Double vision at a distance is generally due to issues with the nerves controlling eye muscles. Eye muscle paralyses, thyroid diseases, myasthenia gravis, or certain neurological diseases can lead to double images when looking at a distance. Astigmatism and dry eyes can also contribute to blurry distance vision and distorted images.