Diplopia, Double Vision, Symptoms and Causes
Double vision, or diplopia, can result when the two eyes are misaligned and aim at different targets. When the viewer's brain registers both images simultaneously, the brain will eventually ignore one of the images. However, ignoring the condition could eventually cause loss of vision in one eye. Additionally, when vision is lost in one eye, normal depth perception and stereo vision are also lost.
Double Vision (Diplopia) Symptoms
In some cases, diplopia can occur without other symptoms. Diplopia symptoms that can occur include:
- Misalignment of one or both eyes (a "wandering eye" or "cross-eyed" appearance)
- Pain with eye movements in one or both eyes
- Pain in and around the eyes
- Weakness in the eyes
- Droopy eyelids
Double vision can be a symptom of various visual conditions that affect children and adults. One such condition is strabismus, or lazy eye, which includes exotropia, esotropia and hypertropia. Double vision can also be a symptom of convergence insufficiency or visual conditions related to head injuries.
Double Vision (Diplopia) Causes
The two most likely diplopia causes are:
- Binocular diplopia. Functional problems in the visual system cause this most common form of double vision.
- Monocular diplopia. A structural defect in the eye's optical system is a less common cause of double vision diplopia. It appears in only one eye.