When a human sees a double image where there should only be one, double vision occurs. The two images can be side by side, one on top of the other, or both. Balance, movement, and reading ability may be impaired by the disease. If double vision affects only one eye, it is monocular. It is binocular if it affects any of the eyes. Treatments depend on the cause and type but include eye exercises, specially designed glasses, and surgery.
Double vision, also known as diplopia, occurs when you see duplicate objects in your vision rather than a unique and clear representation of each object. Double vision can be temporary or permanent. Many events or conditions ranging in severity from a minor concern to a serious or life-threatening concern can cause double vision. Double images can appear horizontally, vertically, or at a tilted angle. Polyplopia is the vision of a single object with three or more representations that contrast each other. According to its origin, it can be of two types:
Binocular: The most common type, where the eyes do not line up correctly with each other. It is usually related to strabismus.
Monocular: A much less common form characterized by double vision generated by just one eye. An eye abnormality, such as astigmatism or cataract, is associated with it.
Stroke, head injury, a tumor of the brain, brain swelling, or aneurysm of the brain:
A head or brain injury, tumor, stroke, or related condition can cause double vision to appear suddenly. After examining you, your ophthalmologist may refer you to a specialist, such as a neurologist or neurosurgeon, for further testing and treatment.
Double vision can also be caused by diseases of the cornea, such as keratoconus and corneal dystrophies. Diplopia of corneal irregularities can often be treated with special contact lenses or dry eye treatments, such as eye drops or point plugs. But sometimes, surgical procedures such as a corneal transplant or Intacs implants may be necessary. Your ophthalmologist can help you determine the best treatment for your double vision.
Many people who suffer from dry eyes can benefit from eye drops, earplugs, eye vitamins, eyelid hygiene techniques, or a combination of all of these treatments.
If you've had LASIK, PRK, or any refractive surgery to help you see better without glasses or contact lenses, you may experience temporary double vision due to changes in your corneas. An uneven corneal surface, caused by the surgery itself or by dry eyes after the procedure, can cause light rays to scatter rather than focus properly. This problem usually goes away a few days to weeks after surgery. In some cases, a second laser vision correction procedure may be necessary to eliminate diplopia.
Cataracts can also cause double vision. This is because the opacity of the eye's natural lens can cause light rays to scatter in different directions, creating multiple images, especially when looking at lights. Cataract surgery will generally eliminate this problem.
Cranial Nerve Palsy:
Paralysis or lack of control of one or more muscles that govern the location and teaming of the eyes due to cranial nerve paralysis may also cause double vision. Diabetes, brain injury, stroke, multiple sclerosis, meningitis, elevated blood pressure, blocked arteries, or aneurysm can cause cranial nerve paralysis.
Determining the cause can be more difficult. If you have double vision, your symptoms and visual experiences will help in the diagnosis. When you visit your doctor, they will take note of your symptoms and run some tests to look for additional vision problems. They will also likely perform a brief test to diagnose the type of diplopia. Once you have a diagnosis of diplopia, the work of finding a cause begins. To do this, your doctor will likely perform three types of tests:
Pay attention to the present condition of your health:
You and your doctor may spend some time updating your medical history. This includes:
A complete history of your symptoms: Fully describing your vision problems to your doctor can help you rule out possible causes and decide which tests may be helpful. Make sure to tell your doctor about any unusual symptoms you've experienced, even if you're not sure they're related to your vision problem.
Your personal health history: Your doctor may consider underlying factors such as diabetes, thyroid problems, or neurological disorders that could be causing your vision problems.
Your family health history: If your family members had vision problems or disorders that can cause double vision, tell your doctor. These problems can be a good starting point for your diagnosis.
A complete physical exam can help your doctor find and identify possible causes of your double vision. This exam may include:
blood tests to look for an infection
eye exam and dilated eye exam
eye movement tests
blood sugar readings
imaging tests, such as a CT scan or MRI
This will depend on the underlying cause.
Treatment for monocular double vision:
Treatment will depend on the cause.
This refers to an abnormally curved cornea. Corrective glasses or contact lenses can often counteract curvature and correct the passage of incoming light to the eye. Laser surgery is another option. This procedure includes laser reshaping of the cornea.
Surgery is usually the best option. The surgical procedure removes the clouding and the cause of double vision. Complications include infection, pain, and possibly continued blurred or double vision, but prompt treatment can usually resolve them.
If the eyes don't produce enough tears or dry out too quickly, they can become inflamed and painful. This can result in double vision. Oftentimes, a prescription for tear replacement eye drops will relieve symptoms.
Treatment for monocular double vision:
This will depend on the underlying cause.
Using an opaque contact lens
Injections of botulinum toxin (Botox) into the eye muscles, causing them to remain relaxed
Wearing an eye patch
Surgery on the eye muscles to correct their position
An adhesive prism, placed between the eyes in the center of the glasses frame, can also help realign the images from each eye
When to visit a Doctor?
To assess the cause, double vision often needs a doctor's examination. Double vision is a symptom that something abnormal is happening within your eye, brain, or nervous system. The problem needs a full evaluation to discover the cause. In many cases, the extra image you see in your field of vision is the result of a treatable condition. But urgent medical attention is needed for any unexpected changes that occur in your vision. Some conditions need urgent medical attention to prevent permanent vision loss or life-threatening complications.
Prevention of diplopia begins with prevention of the underlying cause. To keep your eyes safe, here are some tips:
Manage your diabetes: Diabetes patients who follow treatment plan s have a lower risk of developing double vision. Also, because type 2 diabetes can develop as a result of lifestyle, people who eat a healthy and balanced diet, exercise a lot, and maintain a healthy weight are much less likely to develop diabetes and subsequently double vision.
Prevent the development of cataracts: Keep your eyes healthy and avoid cataracts by wearing sunglasses, abstaining from smoking, and eating a healthy diet.
Soothe dry eyes: Keeping your eyes well lubricated can help prevent double vision. Even, through excessive computer use, aim to reduce eye pressure, which can lead to dry eyes.
Protect yourself from head injuries: Avoid head injuries by wearing a seat belt in the car, a good helmet when riding a bicycle or motorcycle, and a helmet and appropriate glasses when using large machinery and playing sports.
They include neurological conditions, such as myasthenia gravis or multiple sclerosis, or they may be associated with a systemic disorder, such as hyperthyroidism. It can also be a symptom of a stroke, aneurysm, or head or facial trauma, especially around the eye socket.
Double vision can occur with one or both eyes. If it's in one eye when the other is closed, it's less of a concern but still serious. If it occurs when both eyes are open, it could indicate a greater disorder.