Have you ever been watching a television show, reading a book, or taking a walk, only to be hit with a sudden case of double vision?
Also called diplopia, double vision can be alarming when it seemingly comes out of nowhere. While many of its causes aren't serious and double vision is quite common, learning to recognize the signs and symptoms associated with diplopia can help you find the cause and the right solution.
Now, let's explore double vision, what causes it, and what you can do to treat symptoms if they start.
Key takeaways
- Diplopia (double vision) occurs when a person sees two images of a single object
- There are two main types of double vision: monocular double vision (affecting one eye) and binocular double vision (affecting both eyes)
- A proper diagnosis of double vision requires a thorough eye examination by a trained professional
See Related: What Does Axis Mean On My Prescription?
What is double vision?
Diplopia is the term used to describe seeing two images of a single object.
Double vision may happen suddenly, or it may be due to another condition. It can occur alone or alongside a wide variety of other medical symptoms.
Double vision may be a symptom of certain spinal cord or neurological conditions that affect the nerves controlling eye muscles and pathways that support the vision processing of one eye or both eyes.
How does double vision occur?
There are various reasons why someone might develop double vision, from an underlying health condition affecting the extraocular muscles and eye movements to structural causes of the eye that may also result in a sudden onset of diplopia.
Double vision can occur due to a neurological cause or a nerve issue. Diabetes, for example, is a metabolic disease that can cause nerve problems. This can lead to the cranial nerves, which connect the brain to the eye muscles to control eye movement, becoming affected and leading to double vision.
Double vision may present as vertical diplopia or horizontal diplopia.
- Vertical double vision: Caused by issues with the eye muscles that move the eye up and down.
- Horizontal double vision: Due to problems with the muscles that move side to side.
Early signs
There are several early indicators of double vision, including:
- Eye strain
- Overlapping vision
- Blurry vision
Double vision can be temporary or permanent, depending on the underlying cause.
You may experience temporary double vision due to common issues like frequent eye strain, dry eyes, fatigue, or even drug or alcohol use. Even some types of head injuries and medications can cause temporary double vision.
What types of double vision are there?
There are two different types of double vision — binocular diplopia and monocular diplopia. Each carries different symptoms and can impact how an image appears in different ways.
Proper diagnosis is necessary for finding the right solution if you are experiencing double vision.
Binocular diplopia
Binocular diplopia is when vision changes occur while both eyes are open and resolve after one eye is closed. This type of vision issue is due to eye misalignment of one eye, also known as strabismus.
Double vision can be caused by certain conditions impacting the cranial nerves and their ability to supply the muscles that control the eyes. Some of these underlying medical conditions might include neurological conditions like multiple sclerosis or myasthenia gravis, and may even be associated with systemic disorders, like hyperthyroidism.
Binocular double vision can also occur as a symptom of a serious health issue. Central nervous system issues can also lead to double vision.
Causes of binocular diplopia
Binocular diplopia can be caused by various existing health issues, such as:
- Multiple sclerosis
- Myasthenia gravis
- Head trauma
- Brain tumor
- Strabismus
- Thyroid eye disease
Head trauma, in particular, can lead to not only double vision, but corneal problems, eye muscle problems, and other visual discomfort, too.
Monocular double vision
Monocular diplopia, which affects one eye, occurs when a person sees two images of a single object while only one eye is open. This can result in shadowy images, such as a ghost image.
Monocular diplopia is more common and traditionally less severe than binocular diplopia.
Symptoms of monocular diplopia
Symptoms of monocular double vision may include:
- Blurred vision
- Seeing shadows
- Headaches
- Eye strain
- Discomfort
These can all present as symptoms when dealing with double vision.
There are many causes associated with this condition, ranging in severity from minor to serious. These can include:
- Cataracts: Characterized by clouding of the eye’s lens, this can scatter light and create double images
- Corneal issues: Certain conditions, like keratoconus, can result in monocular diplopia as the cornea thins and bulges
- Pterygium: This benign growth on the eye’s conjunctiva can encroach on the cornea and result in irregular refraction of incoming light, resulting in diplopia
- Refractive errors: Imperfections found in the eye’s shape, like astigmatism, can lead to double vision due to improper eye focus
Bonus: Are Cat-Eye Glasses in Style for 2025?
How to diagnose double vision
The only way to diagnose diplopia is through an eye exam by a trained eye doctor. A thorough eye exam will entail careful examination of your eye, including the eye socket, eye movements, muscles, and optic nerve. This can help your doctor determine whether your double vision is monocular or binocular. Blood or imaging tests may also be necessary in order to identify the root cause of double vision.
Treatment for diplopia
If you experience sudden vision changes, it's best to schedule an appointment with your eye doctor.
The recommended treatment for diplopia will depend on the underlying condition. For some, contact lenses might be the answer, while for others, surgical intervention, even through an outpatient surgery, may be the solution.
After a thorough eye examination, your optometrist can determine the best course of medical attention if needed. They may prescribe new glasses that correct your eye issues and enable you to see clearly again. While you’re at it, you can purchase a pair or two of high-quality frames that are both fashion-forward and undeniably luxurious.
By seeking treatment at the onset of symptoms, you can prevent lasting vision loss, nerve damage, lens problems, and other serious conditions that may arise if the root cause of diplopia further progresses.
Prism glasses
Special lenses, like those found in prism glasses, can also be prescribed to treat conditions like diplopia and strabismus, as well as some eye muscle disorders.
These prism lenses work by redirecting light rays, which trick the brain into perceiving one image. This is possible through a unique design that calls for a thicker edge and a thinner edge, the apex, on the lens. This shape causes light to bend towards the apex, helping them correct vision problems and helping both eyes see the same image.
Depending on the medical conditions causing your double vision, you may be referred to a different type of medical provider, such as one who can diagnose and treat neurological conditions. From strabismus surgery to cataract surgery, several solutions are available to help the eye heal and restore normal vision.
Conclusion
Your eyesight impacts many aspects of your overall well-being—from your movement to your mental health. That's why identifying any sudden changes is important.
Whether you are dealing with binocular diplopia, monocular diplopia, or another eye issue, getting to the root cause can help you get the diagnosis and treatment you need to improve not just your eyesight, but your health as a whole.
Keep Reading: What Does Sph Mean On My Prescription?
--
Oculus Eyecare is Seattle’s premier optometry practice and optical boutique for those looking to see and be seen in a new way. Located in South Lake Union on Denny Way, Oculus Eyecare offers comprehensive eye care services and exams for individuals and families in Seattle. Click here to schedule an appointment or a personal styling session. To stay connected and learn more, follow us on Facebook, Instagram, and X/Twitter.