Diplopia, commonly referred to as double vision, is a condition that leads to the perception of two images of a single object seen next to each other or overlapping. Polyplopia, which is similar, is when one sees three or more overlapping images of a single object.
It’s important to obtain a medical evaluation if you are experiencing double vision. While not all causes of diplopia are serious, some could potentially be life-threatening. Some causes include:
- Irregularly shaped cornea (astigmatism)
- Inability to produce enough tears (dry eye)
- Cataracts or other abnormalities of the lens of your eye
- Abnormalities of the retina, including macular degeneration
- Thyroid condition
- Stroke or transient ischemic attack
- Myasthenia gravis
- Multiple sclerosis
- Brain tumor
- Head injury
Double vision can exist with no other symptoms. Depending on the specific cause, other symptoms that may be present with double vision include:
- Droopy eyelids
- Misalignment of one or both eyes (a "wandering eye" or "cross-eyed" appearance)
- Pain around the eyes, such as in the temples or eyebrows
- Pain with eye movements in one or both eyes
- Weakness in the eyes or other areas
Your physician will conduct a thorough evaluation to determine the cause of your double vision. This will likely include a detailed history of your symptoms and a physical exam, including measuring visual acuity in each eye and an examination of your eyes’ alignment. If a neurologic cause is suspected, a CT or MRI scan may be required.
Once the cause of your double vision is identified, treatment can be tailored to your needs. In some cases, specialized glasses, contact lenses or artificial tears can correct the problem. Cataracts can be removed with surgery. If there is a neurologic cause for your double vision, emergency treatment may be required.