LivingDiplopia, what is it and why does it occur?

Diplopia, what is it and why does it occur?

Marc is the most successful driver in the motor world and currently holds the record for being the youngest driver to hold the Grand Prix title. The Spanish pro was recently preparing for the Indonesian Grand Prix at the Mandalika street circuit and during the warm-up the rider suffered a heavy crash which, according to spectators, was the rider’s heaviest so far.

In this process, Marc appeared to have suffered a concussion and some minor trauma, after which he was admitted to the nearby hospital. After a thorough examination, doctors ruled out any major injuries and sent him home. While returning to Spain, he had vision problems and visited his ophthalmologist. Then he was diagnosed with his second episode of diplopia. The first case occurred in November 2021, when he suffered a training accident before the Grand Prix of Portugal.

What is diplopia?

Diplopia is the medical term for double vision. It is a symptom, rather than a diagnosis in itself, so we will also explore various possible causes of this phenomenon. A person with diplopia sees two images of everything: any object, person, or image they look at appears double. When your eyes allow you to see an object, the eyes, eye muscles, and nerves all work together in a chain of events to process the image so you see it as it is. But when something goes wrong in any of these steps, the final process of your brain changes. In the case of diplopia, the brain mistakenly perceives the image as two , and therefore you see double vision.

One or both eyes may experience double vision. It can be horizontal (when the photos are displayed side by side) or vertical (when one image is displayed on top of the other). A muscle or nerve condition can cause double vision. It can also be the result of a vision problem, such as a cataract, or a brain disease, such as a stroke. When the source of double vision is identified, it is often possible to fix the problem.

types of diplopia

There are two types of diplopia: monocular diplopia and binocular diplopia. Monocular diplopia is one in which the patient has double vision in one eye. If the affected person is covered, the diplopia seems to disappear. This condition is also quite rare in its occurrence, compared to binocular diplopia. As in the case of the latter, the patient has double vision in both eyes, but if one of the two eyes is covered, the condition is relieved.

What causes diplopia?

Double vision can be caused by a variety of factors, such as problems with the cornea or lens of the eye. Damage to the muscles or nerves that govern eye function and mobility, as well as brain disorders, could be other underlying causes. Some reasons can be small, like astigmatism, while others, like an aneurysm or stroke, can be deadly.

Monocular diplopia is caused by some type of eye damage and therefore the healthy eye can see clearly. On the other hand, binocular diplopia is mostly due to neurological factors: a damaged nerve, neuromuscular disease, or other such underlying conditions.

Corneal problems can be due to: dry eyes, astigmatism (a defective eye condition), eye infections such as shingles, or any scratches or scars from previous diseases. There may also be problems with the lens, such as a cataract, the most common condition of the lens, in which the lens of the eye is cloudy and the patient sees blurry, usually due to some deformation. There are cases of nerve damage that cause diplopia, such as diabetes, Guillain-Barré syndrome, myasthenia gravis disease, and multiple sclerosis.

What nerve is affected?

Diplopia affects three important cranial nerves, the third, fourth and sixth, which play a crucial role in enabling the eyes to see. Mainly, diplopia is caused by problems with cranial nerves III, IV and VI , which regulate the eye muscles. These nerves can be dysregulated or damaged due to diseases such as multiple sclerosis, Guillain-Barre syndrome, and diabetes mellitus, among others.

Temporary paralysis of a single optic nerve is common and can be caused by various factors. It is also linked to some infections (such as Lyme disease) and inflammatory disorders such as giant cell arteritis. However, the most common causes are vascular diseases, such as diabetes mellitus and hypertension. Children with isolated VI nerve palsy (an eye condition) have been observed following ear, nose, and throat infections. The nerves can also be blocked if the orbital bones (eye socket) are traumatically fractured in the event of an accident or injury.

How long does it last?

Diplopia has a certain duration, which is called an episode. Double vision can appear quickly and unexpectedly, with variable duration and intensity depending on the person and the circumstances.

Temporary double vision is induced by stress, exhaustion, and even intoxication, which is usually nothing to worry about. That interaction is delayed when you’re too sleepy or your blood alcohol level is too high. This delay may be due to a mismatch of signals between the brain and the eye muscles.

Intermittent (recurring) double vision may be a sign of a more serious underlying condition with fluctuating accompanying symptoms, such as migraines, high blood pressure, and dry eye syndrome.

Constant (continuous) double vision is the most concerning, as it can indicate a neurological and/or life-threatening problem, such as a head injury, brain tumor, aneurysm, stroke, or multiple sclerosis.

Symptoms and treatment

Double vision is a common complaint among patients. Images can be merged or next to each other. It is suggested to ask about the alignment of the images, if it appears or increases with a specific direction of the eye, and if it is intermittent or constant. It is also a good idea to check if the double vision disappears when you close one eye and if both images are in focus. Ptosis (droopy eyelid), eye pain, headaches, and nausea are possible side effects.

There are several treatment options that successfully help diplopia, the important thing is to identify the cause of it. In the case of minor conditions, you can block or blur the vision of one eye, to enable the other. This can be achieved using an eye patch, contact lens, or Fresnel prism. For a severe case of diplopia, there are surgical options that can treat the underlying conditions, or the diplopia itself to cure double vision.



Double vision causes (s.f.). Stanford Health Care.

Glisson C. C. (2019). Approach to Diplopia. Continuum (Minneapolis, Minn.), 25(5), 1362–1375.

Marc Marquez (s.f.). Honda Racing Corporation.

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Sprabary, A. (2020, 4 de Diciembre). Types of double vision. All about Vision.

‌Tarantino, C (s.f.). Binocular Diplopia: What Is It, Causes, Diagnosis, and More. Osmosis.

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