Double vision

What is double vision or diplopia?

Double vision, formally known as diplopia, can have several causes and may present in different ways. Some people see two images of one object out of a single eye, while others experience double vision through both eyes. It might look like the images are side by side, overlapping, or a mixture of the two. Some people are affected only occasionally, but for others it can be a constant problem. It’s important to see your optometrist as soon as you experience these kinds of symptoms to determine the root cause and appropriate treatment.

Symptoms

You might experience double vision in one eye (monocular) or both eyes (binocular). By covering one eye, you’ll be able to determine which type of diplopia you have. If both eyes are involved, the double vision will disappear as soon as you cover either eye. However, if the double vision remains when you have one eye covered then you have monocular double vision.

You may also experience:

Migraines
Headaches
Feeling sick or nauseous

In some cases, double vision can be a symptom of a more serious underlying condition, which is why it’s important to seek care from your optometrist as soon as possible.

Common causes

Diplopia has many possible causes, depending on which type you have: monocular or binocular.

Monocular

Monocular diplopia only affects one eye and is the least common of the two. It’s usually caused by an eye problem, such as:

Binocular

Most cases of diplopia occur when both eyes aren’t working together properly. Each eye is surrounded by six muscles working together for the eyes to look toward the same point. Weakness in any of the muscles or their nerve supply can lead to binocular diplopia. Rarely, but much more seriously, diplopia can be caused by a condition involving the brain.

People with double vision will see two images of one object at the same time. It might look like the images are side by side, overlapping, or a mixture of the two. Some people are affected only occasionally, but for others it can be a constant problem.

Treatment

As double vision can occur for several reasons, treatment will depend on its underlying cause, and could range from simple eye exercises to minor surgery.

Your optometrist will be able to help determine the best course of action for you. In some cases, they may recommend you visit another healthcare practitioner, such as a neurologist or ophthalmologist for further evaluation and management.

If you experience double vision with pain or severe headache, please seek medical attention immediately.

Next steps

We want to help you see clearly and keep your eyes healthy for as long as possible. If your optometrist detects any signs of an eye condition during your comprehensive eye exam, they will determine an appropriate management plan that suits your needs.

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Reviewed by Dr. Brendon Bjarnason

Dr. Brendon Bjarnason is a Doctor of Optometry located in Edmonton, Alberta at the Southgate Centre. He completed his optometry degree at Pacific University College of Optometry in Portland, Oregon. Currently, Dr. Bjarnason practices primary eyecare, with special interests in retinal disease, myopia control, and contact lenses and also serves on the Alberta Association of Optometrists Tele‑Optometry and Artificial Intelligence subcommittee.

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