Final answer:
Crossed diplopia usually refers to exotropia, an outward deviation of an eye leading to double vision. It is caused by a failure in conjugate gaze and can have multiple underlying causes.
Step-by-step explanation:
Crossed diplopia is a condition that involves having double vision where the images are misaligned horizontally, meaning that it can be eso (inward) or exo (outward) relative to the original target. However, the specific term 'crossed' diplopia typically refers to exotropia, where there is an outward deviation of the affected eye. This is opposite to the inward deviation seen with esotropia. Diplopia signifies a failure in conjugate gaze where both eyes are not properly aligned, resulting in double vision. This condition could have various underlying causes, which may relate to muscular, neurological, or structural abnormalities within the eyes or the brain.