Double Vision

Many conditions may cause double vision (diplopia) such as:

• strabismus
• orbital inflammation, including thyroid eye disease (TED)
• cranial nerve palsy
• multiple sclerosis
• myasthenia gravis
• orbital injury
• stroke
• brain tumor
• inflammation
• vascular malformation
• aneurysm

What Causes Double Vision?

Double vision, medically known as diplopia, is a visual condition where a person sees two overlapping images of a single object instead of the normal single, fused image. Double vision can be caused by various underlying factors, which can be broadly categorized into two main types: binocular diplopia and monocular diplopia.

Binocular Diplopia: This type of double vision occurs when both eyes are open and working together, but they are not properly aligned. Common causes of binocular diplopia include:

1. Strabismus: Strabismus is a misalignment of the eyes, where one eye may turn inward, outward, upward, or downward. This misalignment disrupts the normal coordination of the eyes and results in double vision.
2. Cranial Nerve Disorders: Damage or dysfunction of the cranial nerves that control eye movements (e.g., oculomotor, trochlear, and abducens nerves) can lead to difficulty in coordinating eye movements, causing double vision.
3. Refractive Errors: Significant differences in refractive errors (such as a large difference in prescription between the two eyes) can cause binocular diplopia when attempting to focus on objects.
4. Head Injury or Trauma: Trauma to the head, especially around the eye sockets, can damage the eye muscles or the nerves controlling them, resulting in double vision.
5. Myasthenia Gravis: This autoimmune disorder affects the neuromuscular junction and can lead to muscle weakness, including the muscles that control eye movements.

Monocular Diplopia: Monocular diplopia occurs when the double vision persists even when one eye is covered. It is typically related to issues within a single eye, and common causes include:

1. Refractive Errors: Uncorrected or undercorrected refractive errors like nearsightedness (myopia), farsightedness (hyperopia), or astigmatism can cause double vision in one eye.b.
2. Cataracts: Advanced cataracts can scatter and distort incoming light, causing double vision in one eye.
3. Dry Eye Syndrome: Insufficient tear production or poor tear quality can lead to blurred vision and ghosting of images in one eye.
4. Corneal Abnormalities: Irregularities in the cornea, such as keratoconus or scarring, can cause monocular double vision.
5. Macular Disease: Conditions affecting the macula, the central part of the retina responsible for sharp central vision, can result in double vision in one eye.

It is important to note that double vision can be a symptom of various underlying medical conditions, some of which may be serious. Therefore, anyone experiencing persistent or sudden double vision should seek prompt evaluation by an eye care specialist or a healthcare provider. A comprehensive eye examination and, if necessary, further medical assessments can help determine the cause of double vision and guide appropriate treatment.