Double Vision (Diplopia)
What Causes Double Vision? continued...
Nerve problems. Several different conditions can damage the nerves that control eye muscles and lead to double vision:
Multiple sclerosis can affect nerves anywhere in the brain or spinal cord. If the nerves controlling the eyes are damaged, double vision can result.
- Guillain-Barre syndrome is a nerve condition that causes progressive weakness. Sometimes, the first symptoms occur in the eyes and cause double vision.
- Diabetes can lead to nerve damage affecting the muscles which move the eyes, causing double vision.
Brain problems. The nerves controlling the eyes connect directly to the brain. Further visual processing takes place inside the brain. Many different causes for double vision originate in the brain. They include:
- Increased pressure inside the brain from trauma, bleeding, or infection
- Brain tumors
- Migraine headaches
What Are the Symptoms of Double Vision?
Double vision can occur by itself with no other symptoms. Depending on the cause, other symptoms may be present with double vision, such as:
- Misalignment of one or both eyes (a "wandering eye" or "cross-eyed" appearance)
Pain with eye movements in one or both eyes
- Pain around the eyes, such as in the temples or eyebrows
- Weakness in the eyes or anywhere else
- Droopy eyelids
How Is Double Vision Diagnosed?
Double vision that's new or unexplained needs urgent medical attention. With so many potentially serious causes for double vision, it's important to discover the reason without delay.
Your doctor will most likely use multiple methods to diagnose the cause for double vision. Blood tests, a physical exam, and possibly imaging studies like computed tomography (CT) or magnetic resonance imaging (MRI) are frequently used.
One of the most effective tools in diagnosing diplopia, though, is the information you can provide. You can make the diagnosis for double vision more accurate by answering several questions beforehand.
- When did the double vision start?
- Have you hit your head, fallen, or been unconscious?
- Were you in a car accident?
- Is the double vision worse at the end of the day or when you're tired?
- Have you had any other symptoms besides double vision?
- Do you tend to tilt your head to one side? Look at old pictures, or ask family -- you may not even be aware of the habit.
Now, focus on something unmoving in your field of vision -- a window or a tree.
- Are the two objects side by side, or is one on top of the other? Or are they slightly diagonal? Which one is higher or lower?
- Are both images clear but simply unaligned with each other? Or is one image blurry and the other clear?
- Cover one eye, then uncover it and cover the other. Does covering either eye make the double vision go away?
- Pretend your field of vision is a clock face. Move your eyes around the clock, from noon to six and up to 12 again. Is your double vision worse at any clock position? Does any position make your double vision improve?
- Tilt your head to the right, then to the left. Do any of these positions improve the double vision, or make it worse?