Double vision – also called diplopia – will make you see two separate images of a single object.

Double vision is a symptom to take seriously. Some causes of diplopia are relatively minor, but others need urgent medical attention.

Double vision may be temporary or permanent. Double vision can be due to a number of different events or conditions ranging in severity from a minor concern to one that is serious or life threatening.

The dual images can appear horizontally, vertically, or at a tilted angle.

Double vision can occur in one or both eyes, and can be caused by several different conditions.

There are several different types of diplopia, and many different causes. Sometimes, double vision can be a symptom of a serious underlying disease or condition. For that reason, if you encounter double vision at any time, you should make an appointment to have your eyes examined straight away.

Children with double vision may frequently cover one eye, or they may tend to squint or turn their head in an unusual way to try to see properly.

Binocular diplopia

Binocular diplopia is the most common type of double vision. It occurs when your eyes don’t align with each other as they normally would. Those with binocular double vision will find that covering either eye gets rid of the double image.

Binocular double vision is usually caused by a squint, but if it occurs suddenly, it could be a symptom of a much more serious medical condition. Diseases of the thyroid or arteries, along with diabetes, multiple sclerosis, stroke and a number of other serious conditions can cause double vision. It’s therefore essential to make an appointment to have your eyes examined as soon as possible if you have double vision.

Monocular diplopia

Monocular diplopia is double vision in one eye only, and is much less common than binocular diplopia. If you have monocular double vision, only covering the affected eye will make the double image disappear.

Monocular double vision is usually caused by an abnormality within the eye itself, such as a refractive error like astigmatism , or a rare type of cataract. It can also be caused by abnormalities of the iris, lens, or fluid within the eye, and even dry eye.