Common Causes Of Double Vision

Dry eyes, infections, cataracts, or even diabetes are all potential causes of double vision, according to Stanford Health Care. Also known as diplopia, this condition can affect one or both eyes and may come and go. Since you are seeing two images instead of one, you may have difficulty reading and moving around. Treatment depends largely on the cause.

First of all, don't fret. While it's true that double vision can indicate a stroke or aneurysm, it may also be due to eye strain, fatigue, or tiredness. A good example is computer vision syndrome, or digital eye strain. This condition can result from poor lighting, screen glare, or too much screen time and tends to affect those who use the computer regularly. One of its main symptoms is double vision, explains Cedars-Sinai. You may also experience eye discomfort and fatigue, blurred vision, dry eye, headaches, or excessive tearing. These symptoms should subside when you take a break from the screen, but they may last longer in some cases.

Double vision isn't always due to a serious problem, but you should still get it checked. In rare cases, it could be a symptom of nerve, brain, or eye muscle problems. 

Why are you seeing double?

Stanford Health Care explains that double vision can have a number of causes ranging from dry eye or astigmatism to brain tumors. However, if you're having a stroke, aneurysm, or brain tumor, you'll most likely experience other symptoms as well. 

A stroke, for example, may also cause blurred vision, confusion, difficulty speaking, arm or leg weakness, dizziness, and severe headaches that occur out of the blue (via Health). Brain tumors, on the other hand, are likely to cause seizures, balance problems, hearing or vision loss, and cognitive impairment, according to Mather Hospital.

Sometimes, double vision is a symptom of diabetes, Guillain-Barre syndrome, or other disorders affecting nerve function, reports Stanford Health Care. Diabetes, for instance, can damage the nerves responsible for eyelid and eye movement. You may also experience numbness and tingling in the limbs, digestive distress, nausea, or dizziness when standing up (via the University of Chicago). Guillain-Barre syndrome, another potential cause of double vision, causes your immune system to attack the nerves, explains the American Academy of Ophthalmology. Aging can give you double vision, too.

Pay attention to your symptoms

Diplopia alone is rarely a cause of concern. Pay attention to your body and take note of any symptoms you may experience. "Double vision in one eye is caused by an eyeball problem, not a neurologic or brain problem," says neuro-ophthalmologist Lisa Lystad (via the Cleveland Clinic). This condition is known as monocular diplopia. 

If you have binocular diplopia, you will only see double when both eyes are open. If you close or cover either eye, this symptom should go away. Generally, binocular diplopia indicates a more serious problem. Call 911 if you also experience sudden numbness or weakness in one arm or leg, loss of balance, sudden severe headaches, or other signs of a stroke, recommends the Centers for Disease Prevention and Control.

Reach out to your doctor, especially if double vision persists for several hours. He will perform a physical examination and refer you to a specialist. About 70% of cases improve with surgery or medication, depending on the cause (via WedMD). For chronic double vision, your doctor may prescribe special glasses with prism lenses.