Webster's Revised Unabridged Dictionary · 1913

Diplopia , noun

[New Latin diplopia, from Greek {not transcribed} double + the root of {not transcribed} sight: compare French diplopie.]

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.

Also: Diplopy