Can using a smartphone with only one eye open lead to temporary blindness?There was a recent report of two people who temporarily lost sight in one eye after using their smart phones whilst lying in bed, but this should not cause alarm, experts say.
However, the incidents do point to the importance of using your digital devices smartly to avoid eye strain. The women in question lost their vision for up to 20 minutes in one eye after reading their phones in the dark while lying in bed with the other eye covered by a pillow.
This story was written up in the New England Journal of medicine in a paper called “Transient smart phone ‘blindness’”. The paper was led by Gordon Plant of Moorfields Eye Hospital. The women’s symptoms occurred only after several minutes of viewing a smart phone screen in the dark. The authors hypothesised that their symptoms were due to differential bleaching of the
The authors hypothesised that their symptoms were due to differential bleaching of the photo pigment in the retina, with the viewing eye becoming light adapted, whilst the eye blocked by the pillow was becoming dark adapted. Subsequently, when both eyes became uncovered in the dark, the
Subsequently, when both eyes became uncovered in the dark, the light-adapted eye was perceived to be ‘blind’ and this discrepancy lasted several minutes, reflecting the time course for the scotopic recovery after a bleach by the light from the smart phone. Two of the authors then went on to do a study on themselves, looking at a smart phone in scientific conditions and found that it took several minutes to recover visual sensitivity when just using one eye.
Although most people view the screen with both eyes open, people also often do look at their smart phones while lying down and when one eye can inadvertently be covered and, since smart phones are now used around the clock, the manufacturers are producing screens with increasing brightness to offset the background ambient luminance and therefore make it easier to read. Therefore presentations like the two women cases described in the New England Journal of Medicine article are likely to be more frequent.
You need to be aware of this risk so that you do not get worried that there may be something wrong with your eyes. The best thing is not to use your mobile phone or tablet after 8 or 9 o’clock at night and try and have good quality screen-free time.
If you are worried about your eyes and smart phone use, see an optometrist or ophthalmologist for full assessment.