What is "diplopia"

Diplopia \Di*plo"pi*a\, Diplopy \Dip"lo*py\, n. [NL. diplopia, from Gr. ? double + the root of ? sight: cf. F. diplopie.] (Med.) The act or state of seeing double.

Note: In crossed or heteronymous diplopia the image seen by the right eye is upon the left hand, and that seen by the left eye is upon the right hand. In homonymous diplopia the image seen by the right eye is on the right side, that by the left eye on the left side. In vertical diplopia one image stands above the other.

n. (context pathology English) An ophthalmology condition where one perceives two images; double vision.

n. visual impairment in which an object is seen as two objects; "diplopia often disappears when one eye is covered" [syn: double vision]

Diplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, diagonally (i.e., both vertically and horizontally), or rotationally in relation to each other. It is usually the result of impaired function of the extraocular muscles (EOMs), where both eyes are still functional but they cannot converge to target the desired object. Problems with EOMs may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves ( III, IV, and VI) that stimulate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins.

Diplopia can be one of the first signs of a systemic disease, particularly to a muscular or neurological process, and it may disrupt a person’s balance, movement, and/or reading abilities.