Transient Smartphone Blindness #illumedati #medtwitter

Hey everyone, it’s Medicine Mondays… except it’s a Tuesday. So for some reason, this didn’t get posted yesterday and I’m not really sure why. Anyways, let’s talk about Transient Smartphone Blindness.

Stock Photo from: Pexels

What is Transient Smartphone Blindness?

Well, it’s kind of exactly what it sounds like. It’s blindness that is temporary (transient) caused by using your smartphone in a particular way.

This actually isn’t new, it was described back in 2016 by the New England Journal of Medicine and reported about by The Guardian. However, a colleague of mine recently started having these symptoms and was given this diagnosis. Given how ubiquitous smartphones have become, I thought it was important to go over it here today.


First, let’s imagine the symptoms — you’re blind in one eye. You literally can not see for a few minutes, or even up to 15 minutes. I can only imagine how unsettling and scary this is. Normally, because of the conditions necessary for this to occur, these individuals are at home and it’s night time. You close your “good eye” and all you see is darkness. You do this over and over again for up to 15 minutes, hoping your vision comes back. Until it finally does.


The first time this happens you are relieved when your eyesight comes back. It must have been something with work, or you were just too tired, or maybe you aren’t eating right or something… right? You’ll be more careful next time.

But then it happens again. 

Now it’s time to see a doctor, but without context, they can’t figure out why it’s happening. They start a workup for diabetes or multiple sclerosis or anything that can cause blindness. You see a neurologist and an ophthalmologist. The work-up continues — and nothing is wrong.

Then you may start questioning yourself… Am I causing this? Did I imagine this? WHAT IS WRONG WITH ME.


Tired of giving your presentation/history over and over again, you’ve now shortened it into a sentence. I have this blindness that occurs for about 15 minutes, and no one can figure out what’s wrong with me. Then finally someone asks:

“Do you have a smartphone?”

Yes, of course I do. Doesn’t everyone have a smartphone?

Do you use it at night? In bed?


Laying down?

Sure, sometimes, I guess.

On your side?


Which side?

Usually my left side. (or right side)

You have transient smartphone blindness. Stop using your smartphone in your bed at night while laying down and it’ll stop.

[[[ RELIEF ]]]


That’s it?

Yes. That’s it.

From NEJM:

“When the patients were seen in our neuro-ophthalmic clinic, detailed history taking revealed that symptoms occurred only after several minutes of viewing a smartphone screen, in the dark, while lying in bed (before going to sleep in the first case and after waking in the second). Both patients were asked to experiment and record their symptoms. They reported that the symptoms were always in the eye contralateral to the side on which the patient was lying.” (emphasis mine)


“We hypothesized that the symptoms were due to differential bleaching of photopigment, with the viewing eye becoming light-adapted while the eye blocked by the pillow was becoming dark-adapted. Subsequently, with both eyes uncovered in the dark, the light-adapted eye was perceived to be “blind.” The discrepancy lasted several minutes, reflecting the time course of scotopic recovery after a bleach.” (emphasis mine)

I’m not sure it’s been studied, but the implication is that the longer you were to lay in bed starting at your smartphone screen with one eye covered, the longer it would take for recovery.

Why talk about this now?

Well, I imagine this becoming a more and more common in presentation. While some people may immediately google “night blindness” or “blindness in bed” and may eventually stumble upon this diagnosis, others may not find it. This would be very anxiety-inducing.

You could save your patient a lot of distress (and a potentially unnecessary workup) if you ask the right questions. Medical students and interns are usually the first line when it comes to gathering patient history while doing admissions. By knowing this extra little bit of knowledge and asking the right questions, you would be this patient’s savior.

That said, just because a person fits the description/presentation perfectly, that doesn’t mean you’re done. The demographic which is affected by this is not well understood, but so far it’s been women between 22 yo and 40 yo. As you can imagine, the demographic overlap with multiple sclerosis is there. However, the presentation/symptoms should not be the same. The key differences would be that the symptoms here are brief and painless, while optic neuritis should last longer than that and usually be painful.

Even so, after telling the patient that they likely have transient smartphone blindness, it’s probably a good idea to educate them on what to look for with true optic neuritis. I can imagine a scenario where a patient develops transient smartphone blindness, is diagnosed as such and then later minimizes other symptoms which may be related to multiple sclerosis. This would end up delaying diagnosis and treatment.

Remember this:

Transient smartphone blindness should be brief and painless.

Contrast this against optic neuritis which should be temporary (but not brief) and painful.

Take home message

Long story short, if someone comes to you with complaint of transient (temporary) blindness lasting less than 20 minutes. Your first question should be:

“Do you use your smartphone at night?”


Transient smartphone blindness is a real thing. Probably more common than we think.

Knowledge of this entity will do wonders for your patient for early diagnosis, and ease their distress.

Transient smartphone blindness should be brief and painless.

Contrast this against optic neuritis which should be temporary (but not brief) and painful.

“Do you use your smartphone at night?”


Medicine Mondays Sensei


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