Double vision is also known as diplopia. Double vision can happen in 1 or both eyes. If you have double vision, you see 2 images when you are looking at a single object.1
While this problem can be temporary, it may be a sign of something more serious or even life-threatening going on in your brain. Seeing double is not something to ignore. Your doctor will be able to determine the type of double vision you are having and the best treatment for you.1
If you have dry eye disease and experience occasional double vision in 1 eye, you probably have questions. Learning what double vision is and how it may relate to your dry eye symptoms can help you talk to your doctor and get the care you need.
What causes double vision?
Double vision can occur due to a wide variety of causes. Your doctor will first determine if your double vision is in 1 or both eyes. Depending on this, you may need extra testing to find the cause of the double vision.
Some causes of double vision may include:1-5
- Dry eye disease
- Astigmatism, an irregular shape of the cornea of the eye
- Cataracts, clouding of the lens of the eye
- Misalignment of the eye muscles
- Certain types of migraine, a brain condition that causes other debilitating symptoms beyond headaches
- Stroke, which can occur if blood flow to the brain, eye, or eye muscles is slowed or stopped
- Brain aneurysm, a bulge in a blood vessel inside the brain that can leak or burst
What is monocular diplopia?
Double vision in 1 eye only is called monocular diplopia. Monocular diplopia is usually caused by a problem in or on the eye itself, not a problem inside the brain. The most common cause of this type of double vision is chronic dry eye disease.2,5
The surface of your eye is called the cornea. The cornea serves to protect the eye and to help bend the light for normal vision.6
Under normal circumstances, the cornea has a layer of tears, known as the tear film. The tear film covers the cornea and keeps the surface smooth. The tears are continuously smoothed over the eye with every blink. Without the moisturizing tears on its surface, the cornea is not a polished lens. Instead, the cornea is rough like sandpaper.6
As a result, light scattering on the rough, irregular surface of the cornea can cause you to perceive double or even multiple images of a single object.5
How is double vision treated?
Treating symptoms of chronic dry eye depends on the cause. Your doctor will need to perform a detailed exam and ask you questions about your symptoms.
Double vision may be life-threatening. Immediate medical attention is important to rule out a medical emergency. Talk to your doctor about various treatments and therapies that may help with the symptoms you have related to chronic dry eye and double vision.