The aetiology of transient monocular vision loss is not necessarily thromboembolic, and careful history-taking is crucial in making the correct diagnosis.
A previously healthy woman in her thirties was referred to our outpatient stroke clinic on suspicion of recurring amaurosis fugax in her right eye. The ophthalmic and neurologic examinations were normal. A review of the medical history revealed that her symptoms occurred in connection with using her smartphone in bed, typically while lying on her left side with the left eye covered by the pillow. When standing up from the bed again with the lights turned off in the bedroom, she noticed vision loss in her right eye.
We concluded that the patient had experienced transient smartphone blindness. This phenomenon can occur when monocularly using a smartphone under scotopic lighting conditions; only the occluded eye adapts to darkness, and the other eye is perceived to be blind if looking away from the bright smartphone screen.
Erik Eriksen, Øystein Kalsnes Jørstad Om forfatterne