Two women experienced temporary blindness in one eye in cases of suspected transient smartphone blindness, according to new research.
UK researchers subsequently discovered that both cases occurred after the women looked at a smartphone screen, lying on one side in bed in a darkened room.
In the paper published in the New England Journal of Medicine, the scientists hypothesise that one eye, covered by the pillow, adapted to the dark, while the eye on the smartphone became adapted to the light – and thus this eye became ‘blind’ away from the bright screen.
As temporary, monocular vision loss can be attributed to a blood vessel clot, the researchers stressed the importance of practitioners keeping such cases in mind and taking a detailed history of the symptoms from a patient.
In an ethically approved experiment to confirm that the symptoms were due to differential bleaching of photopigment, two of the paper authors viewed a smartphone screen using one eye. The reduction in the eye’s retinal sensitivity and its recovery over several minutes was tracked.
The paper explained: “People frequently use smartphones while lying down, when one eye can be inadvertently covered. Smartphones are now used nearly around the clock, and manufacturers are producing screens with increased brightness to offset background ambient luminance and, thereby, allow easy reading.
“Hence, presentations [of temporary smartphone blindness] are likely to get more frequent.”
The researchers, one of whom received Fight for Sight funding, concluded that a detailed history taking and an understanding of retinal physiology can reassure patients and practitioners “and can avoid unnecessary anxiety and costly investigations.”
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