Double vision, also known as diplopia, is an eye disorder that makes one see two overlapping images of the same object. The image could be distorted vertically, horizontally, or even diagonally in severe cases. There are multiple causes, several risk factors, and underlying health complications that trigger this condition. However, early diagnosis and prompt treatment can help manage double vision to a great extent. Here is what one can expect:

Causes and risk factors
Sudden double vision can develop in one or both eyes due to the following reasons.

Cornea damage: Cornea is one of the most important components of the eye that helps focus light into the organ. However, eye conditions like astigmatism, dry eyes, a shingles infection, or even injury to the cornea distort the surface, making it difficult for the eye to focus incoming light. This triggers a sudden double vision, requiring immediate attention to prevent permanent damage.

Lens damage: The eye lens captures the light filtered by the cornea and focuses it onto the retina at the back of the eye. Any damage to the lens brought on by underlying health complications or injury triggers double vision. One of the most common conditions that affect the lens is cataracts. Here, a cloudy layer develops behind the lens, distorting vision.

Weak eye muscles: Six primary eye muscles coordinate the movement of the eyeball to focus on peripheral objects. These muscles control the side-to-side, top-to-bottom, and circular movement of the eyes. Muscle paralysis brought on by Graves’ disease can lead to a vertical double vision wherein two images appear stacked on top of each other. Weakened muscles can also prevent the eyes from aligning properly, resulting in distorted or duplicate images.

Nerve damage: Underlying health complications and neurological disorders can affect the functioning of the nerves. If the nerve pathways are damaged, the brain cannot communicate with the eyes to receive signals and clearly process images. Metabolic diseases like diabetes trigger a blood glucose imbalance that affects the nerves. Further, the Guillain-Barré syndrome can trigger muscle weakness affecting eye movement. Multiple sclerosis, a disease of the central nervous system, also damages the nerves that control eye functions. Additionally, certain autoimmune conditions like myasthenia gravis target the neuromuscular joints that control eye movements.

Brain disorders: Brain aneurysms, brain tumors, migraines, internal bleeding, and stroke are all serious disorders that prevent the brain from properly processing images. So, these underlying complications disrupting visual communication can be major causes of double vision.

Common symptoms
Headaches, pain over the eyebrows or around the temples, droopy eyelids, misalignment that causes wandering eyes, and general weakness are all typical signs and symptoms of diplopia. In some cases, one might experience nausea and persistent pain with eye movement in any direction. These symptoms may develop abruptly without a noticeable pattern. It is possible to experience double vision that is constant or intermittent, primarily affecting near or far vision. The issue can also be monocular (affecting one eye) or binocular (affecting both eyes). Vision can be split either vertically, horizontally, or diagonally depending on the severity of the condition.

Diagnosis
Diagnosing begins with a simple physical exam and blood tests. Ophthalmologists will try to understand the progression of the condition by asking questions regarding the symptoms. Based on the pattern and severity of the symptoms, the doctor may recommend computed tomography (CT) scans or detailed magnetic resource imaging (MRI). A series of eye exams will be conducted in the meantime to see how difficult or confusing it is for the patient to focus on a particular point.

Treatment
As the condition has multiple triggers, treatment options can vary depending on the underlying health complications.

Monocular double vision: If the image distortion affects a single eye, the causes could be astigmatism, dry eyes, cataracts, or corneal misalignment. For astigmatism, ophthalmologists may prescribe corrective glasses to compensate for the uneven curvature of one’s cornea or lens. The glasses can redirect light and improve focus. Laser surgery is another treatment option to repair damaged corneas or clear cataracts, helping improve focus and restore vision. For dry eyes, multiple prescriptions can help lubricate the eyeball and restore natural tear production.

Binocular double vision: The treatments for binocular diplopia are not as elaborate and can vary depending on the progression of the symptoms. In some cases, wearing glasses or opaque contact lenses can help manage the condition. Ophthalmologists also recommend eye exercises to strengthen the muscles that control movement. For moderate to severe vision problems, a small surgery can be done to correct the positioning of the eye muscles.