Vision Loss Caused By Bedtime Smartphone Use
One woman was so scared by her symptoms that she thought she'd suffered a stroke - now doctors have issued a warning.
Thursday 23 June 2016 12:10, UK
Doctors have warned that temporary blindness can be caused by using a smartphone in bed.
The problem occurs when people look at their bright phone screen in a dark room using only one eye.
The solution: use both eyes.
Dr Gordon Plant said: "It's because it's taking many minutes to catch up to the other eye that's adapted to the dark."
The condition has been detailed in the latest edition of the New England Journal of Medicine.
It described two women aged 22 and 40 experienced "transient blindness" for months.
They complained of recurring episodes of temporary vision loss, which lasted for up to 15 minutes.
They went through scores of tests but doctors could not find anything wrong - until Dr Plant, from London's Moorfields Eye Hospital, asked exactly what they were doing when the episodes occurred.
They said they were checking their phones on their side, with one eye covered by a pillow.
When they put the phone down, the eye could no longer see.
One of the women was concerned that she was suffering a stroke when it happened for the first time, but instead it turned out to be harmless.
The team of experts from Moorfields Eye Hospital, along with academics from several London universities, published their warning in the medical journal.
"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," the report said.
"Hence, presentations such as we describe are likely to become more frequent."