Visual illusions

In contrast to a visual hallucination which is defined as a visual perception that is not associated with external visual stimuli, a visual illusion is a distortion or modification of a real visual image (Pelak and Liu, 2004). The following webpages will provide examples from the medical literature and from migraine sufferers' self-reports in the internet for various types of visual illusions that may occur as visual migraine aura symptoms.

Dysmetropsia, i.e., macropsia, micropsia, pelopsia and teleopsia (objects appearing larger, smaller, nearer and further away)

Tilted vision, inverted vision and other forms of illusory rotation

Diplopia (double vision)

Polyopia (vision of multiple images)

Visual perseveration, i.e., prolonged afterimages, palinopsia (the persistence or reappearance of an image of a previously viewed object), illusory visual spread (the illusory extension of the visual perception over an area greater than that which the stimulus-object would be expected to excite)

Cinematographic vision (visual illusion whereby the normal perception of moving objects is replaced by seeing a series of "stills" as in a film run too slowly)

Corona phenomenon (extra-contour around objects)

Illusory visual splitting

Metamorphopsia (distorted vision)

Facial metamorphopsia (distorted vision of human faces)

Mosaic illusion (fracture of the visual image into pieces dovetailed together as in a mosaic)

Autokinesis (illusion of apparent movement of stationary objects)

Are you acquainted with similar phenomena associated with your migraine attacks? Please contact Dr Klaus Podoll if you wish to share and discuss your experiences.

References

Norton JW, Corbett JJ. Visual perceptual abnormalities: hallucinations and illusions. Semin Neurol 2000, 20: 111-121.
Pelak VS, Liu GT. Visual hallucinations. Curr Treat Options Neurol 2004; 6: 75-83. (See also here.)