Diplopia (double vision)

Diplopia, or double vision, is the simultaneous perception of two images of a single object. It can be horizontal, vertical, tilting, or a combination of all of these. Depending on the cause and severity, it can be intermittent or constant in nature, and is often disorientating and debillitating for the sufferer.


 Horizontal diplopia


What causes diplopia?

It can have many causes, but is usually the result of impaired function of one or more of the 6 extra-ocular muscles, where both eyes are still functional, but have lost the ability to work together as a pair.



   Side view of the right eye, showing the extra-ocular muscles


The 6 extra-ocular muscles are the superior rectus, the inferior rectus, the medial rectus, the lateral rectus, the superior oblique and the inferior oblique.

These 6 extra-ocular muscles are innervated by 3 of the 12 cranial nerves-the third, fourth and sixth. If the nerves or muscles are prevented from working properly, this can result in diplopia.






                                                                               Front view of the right eye


What to do if you have diplopia

If you suddenly experience diplopia, you should seek a referral to your local eye clinic or A&E department, where you may need to have medical investigations to discover the cause of the diplopia.

How is it treated?

The appropriate treatment for binocular diplopia will depend upon the cause of the condition producing the symptoms. In many cases, the diplopia is transient. However, the first concern must be to identify and treat the underlying cause of the problem.

Following this, most cases of diplopia are treated initially using temporary prisms, which can join the 2 images. Other treatment options include permanent incorporation of prisms into glasses, eye exercises, covering one eye, or if the symptoms are persistent, strabismus (squint) surgery and/or Botox injection.