What is Double Vision?

Double Vision is known as ‘diplopia’ in medical terms. It commonly occurs with eye movement disorders and can be a distressing and disabling symptom that impacts significantly on daily activities at work and home.

Diplopia can be divided into two main categories :

monocular diplopia and binocular diplopia.

This article will focus on binocular diplopia, which occurs due to a problem with eye movements, and results from a misalignment of the eyes. This is known as ocular misalignment.

How do I know if my Double Vision is ‘binocular diplopia’ ?

It is only present when both eyes are open and disappears when closing either eye.  This is different to ‘monocular diplopia’ , where the double vision still persists when you close either eye.

In what ways does ‘binocular diplopia’ present?

Binocular diplopia can present in different ways. Images may be seen side by side (horizontal diplopia), one above the other (vertical diplopia) or a combination of both (oblique diplopia). For some people there can also be a tilting component. The amount of separation of images can also change depending upon the direction of gaze, or how far away the object or person of interest is.

My eyes tend to ‘drift’, is it normal?

Yes and no. It is normal for most of us to have an underlying tendency for the eyes to drift in, or out slightly. This drift is controlled using our ability to maintain ‘binocular single vision’. However, ‘binocular diplopia’ happens when a person’s ability to maintain binocular single vision is disrupted. There are a lot of reasons why your ability to maintain binocular single vision is affected , some of which are benign while some causes can be very worrying.

It is not normal when diseases or injury causes limitations to the muscles that move the eye, or damage to the nerves that ‘fire’ these muscles. If the symptoms are new, it’s important to seek medical attention right away, as the cause should be diagnosed as soon as possible. Even if it is long-standing, it is worth seeing a healthcare practitioner to explore possible management options.

How do I manage binocular diplopia?

In some cases, binocular double vision can be improved with medications—if the condition causing it can be treated that way. But not all causes can be fixed with oral medications. Depending upon the cause, for some people it is a temporary problem whilst for others it is permanent. Either way there are management options available that whilst they do not cure the problem can compensate for it and significantly improve quality of life.

Patients with binocular diplopia can be referred to ophthalmologists or orthoptists who are specialists in the assessment and management of eye movement disorders. They will work with  patients and advise on the best way of managing their diplopia.

If you are interested in information on treatment options,  take a look at our guide, 'Treating Double Vision: A Clear and Practical Guide', written by Claire Hazell, specialist orthoptist with years of experience in managing this condition.