Monocular diplopia may be due to repetitive images caused by cerebral polyopia or by ghosting image due to refractive errors or retinal diseases.
12.
The onset of polyopia is not immediate upon perception of visual stimuli; rather, it occurs within milliseconds to seconds of fixation upon a stimulus.
13.
Instead, Cornblath offers a possible pathophysiological mechanism in which polyopia results from the recoding of visual receptive fields in primary visual cortex ( Area V1 ).
14.
Polyopia has been described by patients as images suddenly multiplying . These multiple images can drift, fade, and disappear, depending on the severity of the condition.
15.
The mechanism of infarction differs by patient, but polyopia is experienced most commonly in patients that suffer from epilepsy in the occipital cortex, or in patients who suffer from cerebral strokes.
16.
"' Entomopia "'( from the eye " ), is a form of polyopia in which a grid-like pattern of multiple copies of the same visual image is seen.
17.
However, Bender s theory does not account for recent studies in which fixation did not change and no eye movements were produced while polyopia was experienced, therefore polyopic images were not a result of involuntary eye movements.
18.
Cerebral polyopia has been reported in extrastriate visual cortex lesions, which is important for detecting motion, orientation, and direction . suggesting deafferentation hyperexcitability could be a possible mechanism, similar to visual release hallucinations ( Charles Bonnet syndrome ).
