Diplopia

Diplopia is also known as Double Vision (or Double-Vision).

Diplopia may be described as the simultaneous awareness of two images of the same object. The two images may be

• displaced horizontally, vertically, or diagonally (i.e. both vertically and horizontally) in relation to each other, and/or
• may over-lap each other (to varying extents), and/or
• may be diffuse / blurred / out-of-focus.

Diplopia may occur because the two eyes are unable to move normally such that both are looking at, and focussing correctly, onto a particular object. This may be due to problems with

• nerves controlling movement of one or both eyes,
• muscular problems moving one or both eyes, or
• some mechanical restriction resisting movement of one or both eyeballs in their respective sockets.

Examples of conditions in which the eyes are misaligned such that diplopia may result include squints such as esotropia or exotropia.

In some cases diplopia may occur as a temporary effect or symptom.
For example, temporary diplopia may result from

• intoxication (due to excessive consumption of alcohol),
• certain head injuries, e.g. concussion,
• as a side-effect of some drugs (which, if suspected, should be reported immediately),
• tired and/or strained eye muscles, or
• "crossing" of one's eyes their own eyes intentionally.

As diplopia may be an initial indication of a serious underlying condition, it is reason to seek prompt medical advice in case of concern and especially if accompanied by other symptoms such as fatigue and pain.

More about Ophthalmology: This section includes short definitions of many diseases, disorders, and conditions of the eyes and visual system. For definitions of other terms in this category, choose from the list to the left (but note that this is not a complete/exhaustive list).
Other related pages include the diagram of the eye, and definitions of parts of the eye, a description of the human retina, and definitions of parts of the retina, and the section of short definitions of clinical and surgical procedures re. eyes and human visual system.

For further information see also our section of Books about Ophthalmology.

This Section is about
Diseases and Disorders of the Eyes and Visual System.
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