Two Women Diagnosed with “Smartphone Blindness”

phone in bed
Science & Medicine

I’ve written before about the importance of not using a smartphone (or other electronic devices) in bed at night because the blue light emitted from them can wreak havoc on your sleep pattern. But that’s not all that can happen from using your phone ‘inappropriately.’ Actually, you could even go blind (for a minute).

It’s a rare occurrence, but sometimes after I’ve been using my phone while lying on my side, or squinting to look at the screen without my glasses, I can’t see out of my right eye very well for a couple of minutes. Maybe I should call a researcher, because apparently this happens to other people, too, and now scientists have given the “condition” a name: “Transient Smartphone Blindness.” [1]

I just love when I write an article and I realize the same thing has happened to me, and that it was something caused by me not taking my own advice.

Others Have Experienced ‘Transient Smartphone Blindness’

Something similar to what I experienced has been documented in 2 women from the United Kingdom. Both women reported mysterious vision problems that occurred only at night or first thing in the morning.

In the first case, a 22-year-old woman told her eye doctor that she had trouble seeing out of her right eye at night while she was in bed. This occurred multiple times a week for about a year. Each time, she said she could only see the outlines of objects with her right eye, although she didn’t have any problems with her left eye, and both eyes worked just fine during the day.

Her eye doctor examined her and found that the woman’s vision was normal, and she didn’t have a blood clot.

The second case involves a 40-year-old woman who told doctors she couldn’t see out of one eye when she woke up early in the morning, before sunrise. The vision problem lasted about 15 minutes, and happened off and on for about 6 months.

One Eye Adjusts to Light, While the Other Adjusts to Darkness

Both doctors later learned the women’s vision problems only occurred after they’d been using a smartphone in bed. They hypothesized that, without realizing it, the patients were looking at their phone with just 1 eye, with the other blocked by a pillow while they were lying down.

In this situation, the eye blocked by the pillow becomes adapted to the dark, while the other eye (looking at the smartphone) becomes adapted to the light. When the smartphone is turned off, the eye that adapted to the light is perceived to be “blind,” until it also adjusts to the dark.

Yeah, I feel stupid.

The doctors write in the report, published in the New England Journal of Medicine:

“What the patients are aware of is the differing visual experience between a light-adapted eye … and a dark-adapted eye … at low ambient light levels. As they can see well with the dark-adapted eye, it seems to them that they have lost vision in the eye which — a moment ago — was viewing the smartphone normally.”

The doctors had the patients experiment by looking at their phone with both eyes, and also with each eye individually. They didn’t experience any vision problems when they looked at the phone with both eyes, but if they looked at it with just 1 eye, they were able to recreate the symptoms – and always in the eye that had been looking at the phone.

The doctors tried the experiment, too, because, why not? I guess it’s like people who tase themselves with a taser just to see what it’s like. [2]

Omar Mahroo, an ophthalmologist at Moorfields Eye Hospital in London and an author of the report, says:

“The retina is pretty amazing because it can adapt to lots of different light levels, probably better than any camera. It can reduce its sensitivity, so that when you’re on the beach or in the bright snow you can still see relatively well.”

So now I know what was going on with my own eyes, but it’s not something that I or anyone else should be worried about. Your vision will come back in a few minutes.

Mahroo adds:

“We don’t know of any ill effects.” [1]


[1] NPR

[2] Live Science