Visual disturbance is the characteristic feature of migraine with aura. Scintillating scotoma and obscuration of vision, photopsia, anopsia, zigzag streaks of light, tunnel vision, metamorphopsia, micropsia, macropsia, autokinesis, diplopia and polyopia are some of the known visual disturbances. We report a case of migraine with monocular hemi-field slide for the first time.

A 57-year old lady presented to the neuro-ophthalmology clinic with a few episodes of visual disturbance during summer, when she sat in front of computer at her office and was exposed to the direct sunlight. The episodes resolved spontaneously within half an hour. The visual disturbance was described as a “mosaic” effect with black and white spots in her right field of vision. Simultaneously, the computer screen was noticed to have “split” in two vertical halves, with the right half sliding higher than the left. Her ophthalmic examination was completely normal. She was asked to monitor her future migraine episodes by covering one eye and recording whether the screen “split”. In her subsequent follow up visit, she confirmed that her hemi-field slide was still noticeable with one eye being covered. She was advised to avoid direct sunlight.

She reported significantly less migraine attacks during the winter time.

Hemi-field slide is described as horizontal or vertical diplopia secondary to “splitting” of images, in the absence of ocular malalignment. This has been reported mainly in bitemporal hemianopia secondary to pituitary mass. Bitemporal hemianopia in post-traumatic chiasmopathy, binasal hemianopia in idiopathic intracranial hypertension and heteronymus altitudinal field defect in bilateral non-arteritic anterior ischaemic optic neuropathy are other conditions reported to cause vertical and horizontal hemi-field slide. However, these reports described “binocular” hemi-field slide. In fact, monocular hemi-field slide, which could be considered as one of the rare visual disturbances associated with migraine, has not been reported according to our literature review.