Diplopia: Types, Causes, Symptoms, Complications, Diagnosis, Treatment and Prognosis

It is an alteration of vision that consists of the perception of two images of the same object.

This condition is commonly called double vision . Typically, this vision problem is the result of an underlying condition. Identifying and treating the cause can help you regain your sight and prevent other symptoms from occurring.

There are two types of diplopia: monocular diplopia and binocular diplopia.

You can find out the type of diplopia you have with a simple test: while double vision is occurring, cover one eye.

If the double vision goes away when you cover either eye, you have binocular diplopia. In monocular diplopia, double vision disappears when the affected or “bad” eye is covered, and returns when the unaffected or “good” eye is covered.

Monocular diplopia is the result of a problem with one of your eyes. A problem within your brain or the nerves in your eyes can be the cause of binocular diplopia. Once your doctor identifies what type of double vision you have, he can start looking for the cause.

Causes of monocular diplopia

Monocular double vision occurs due to a problem with one eye and is less common than binocular double vision. Many people with monocular diplopia report that one of the images will be very clear, while the other will fade or disappear.

Causes of binocular diplopia

Binocular diplopia will go away if you protect one eye. Double vision occurs because the two eyes do not work together. People with this type of double vision often report that the two images they see are equally clear.

When to call your doctor

Double vision always requires a doctor’s evaluation to determine the cause. Double vision is a symptom that something abnormal is happening inside 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 any sudden change in your vision requires immediate medical attention.

Some conditions need urgent medical attention to avoid permanent vision loss or life-threatening complications.


Every possible cause of double vision has possible complications. The causes of double vision can range from something easily correctable to something more complicated, such as a chronic illness.

Some people with double vision may experience nausea or vertigo due to the altered field of vision. Others may experience visual tension and sensitivity to light or sounds.

Life-threatening conditions such as infections or brain tumors can cause double vision, but these cases are rare. In these cases, severe eye pain or headache often occur along with visual changes.

Any headache accompanied by vision changes is considered life-threatening and requires immediate medical attention.


The diagnosis of double vision as monocular or binocular is usually straightforward. 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:

1) Take an inventory of your current health status – You and your doctor can spend some time updating your health history. This includes:

A complete history of your symptoms – Fully describing your vision problems to your doctor can help them eliminate possible causes and decide which tests may be helpful. Make sure to tell your doctor about any unusual symptoms you have experienced.

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’s health history: If your family members have vision problems or disorders that can lead to double vision, tell your doctor.

2) Physical exam: 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 pupil exam.
  • Eye movement tests.
  • Toxicity tests.
  • Blood sugar readings.
  • Imaging tests, such as a CT scan or MRI.


Before deciding on treatment, it is important that you and your doctor find the cause of the vision problem. In many cases, vision problems can go away once the underlying problem is corrected or treated.

The most common treatments for diplopia include:

Corrective lenses: glasses or special lenses can correct the vision problem. For example, prisms can be etched into your eyeglass lenses to adjust your vision.

Eye patch or covering: Covering one eye can stop double vision. While this may not be a long-term solution, an eye cover can help control double vision until there is a more permanent solution.

Eye exercises: If your vision problem is the result of tight or weakened eye muscles, your doctor may provide you with “exercises” that can help you regain muscle strength in your eye. As your muscles get stronger, your vision problems should improve.

Surgery: Depending on the cause, you may require surgery to correct any physical problems. Also, people with problems like cataracts or problems inside the eye will likely need surgery at some point. Surgery to correct this problem should also correct any double vision.


People with double vision often make a full recovery. Some people will recover with minimal treatment depending on the cause. Others may need more attention, but still experience a full recovery once their doctor identifies the problem.

Once the underlying cause is treated, the double vision and any other symptoms you are experiencing will go away. In some cases, you will need additional treatment, but most efforts to treat diplopia are successful.

Some common causes of double vision can return. These include cataracts and cranial nerve palsy. In these cases, it is important that you work with your doctor to identify the problem as soon as it begins, so that treatment can begin if vision problems return.