S: AAO – http://www.aao.org/publications/eyenet/200911/feature.cfm?RenderForPrint=1& (last access: 25 November 2014); DRUGS – http://www.drugs.com/health-guide/double-vision-diplopia.html (last access: 25 November 2014)
N: 1. The perception of two images of a single object.
2. From Greek διπλόος “double”, and ὄψ, ὀπός “vision”
3. There are several types of diplopia: Binocular diplopia is the double vision in which the images of an object are formed on noncorresponding points of the retinas. Crossed diplopia is the one in which the image blonging to the right eye is displaced to the left of the image belonging to the left eye, as occurs in exotropia (divergent squint), also called heteronymous diplopia. Direct diplopia is the double vision in which the image blonging to the right eye appears to the right of the image blonging to the left eye, as occurs in esotropia (convergent squint), also called homonymous diplopia. Horizontal diplopia is the one in which the images lie in the same horizontal plan, being either crossed or direct. Monocular diplopia is the perception by the same eye of two images of a single object, due to double pupil, early cataract, irregular astigmatism, or displacement of the lens. Physiological diplopia is the one in normal binocular vision; all objects not on the horopter of the fixated object are doubled throught stimulation of disparate points of the retinae outside the corresponding retinal areas. For nearer objects, the diplopia is crossed; for farther objects, uncrossed. Called also stereoscopie diplopia. Torsional diplopia is the double vision in which the upper pole of the vertical axis of one image is inclined toward or away from that of the other.
4. Cultural Interrelation: Fight Club (David Fincher, 1999) is one of those films with a “twist” at the end. This means that anything is as you expected it to be and you only realise with the revealing ending. However, there are several clues that suggest how is going to be the ending and what is the film’s secret. The Narrator, played by Edward Norton, suffers from diplopia or double visions in several film scenes in addition to the chronic insomnia he has. Without any doubt, this is one of those hidden clues that make you guest the ending.
S: 1 & 3. DORLAND p. 525. 2. COLLINS – https://www.collinsdictionary.com/dictionary/english/diplopia (last access: 29 November 2019). 4. BUSIN – http://www.businessinsider.com/fight-club-twist-ending-easter-eggs-2014-5 (last access: 27 November 2014).
SYN: ambiopia, double vision and binocular polyopia.
S: DORLAND p. 525
CR: amaurosis, amblyopia, blindness, nyctalopia, ophthalmology, strabismus, stye, xerophthalmia.