Cell phone blindness is a phenomenon that involves temporary vision loss in one or both eyes after looking at your phone in a dark room. It usually occurs when one eye is blocked with a pillow or other object.

Cell phone blindness is another name for a phenomenon called transient smartphone blindness. The term first appeared in the New England Journal of Medicine in 2016.

It refers to temporary vision loss, usually in one eye, associated with using a smartphone while lying in the dark. It usually occurs when one of your eyes can see your phone screen and the other is blocked by a pillow or another object.

Although cell phone blindness isn’t serious, some people may find the change in their vision concerning if they don’t know what causes it. Vision loss seems to return to normal within minutes, and there’s no evidence that it causes long-term damage.

Keep reading to learn more about this visual phenomenon.

Cell phone blindness usually occurs when looking at a bright smartphone screen in a dark room when one eye is covered by an object like a pillow.

It’s thought to develop due to one eye becoming light-adapted and the other eye becoming dark-adapted. When you turn off your phone screen, the dark-adapted eye can instantly see well. The eye that could see the phone screen takes some time before it adapts to a dark environment again.

Cell phone blindness has also been reported in both eyes. In these cases, both eyes are light-adapted from looking at a phone screen and take some time before they readapt to a dark environment.

Cell phone blindness involves sudden and painless vision loss, usually in one eye, after looking at a smartphone in low light. Normal vision usually returns within minutes.

In a 2019 case study, researchers reported a 68-year-old woman experiencing this phenomenon. She complained of losing vision in both eyes for several minutes whenever she got up to use the restroom at night.

In a 2021 case study from Norway, a woman reported identical episodes of painless vision loss that appeared like she had a dark lens placed in front of one eye. Her vision gradually returned within 10 to 15 minutes in each case.

Although some people may find changes to their vision concerning, cell phone blindness hasn’t been linked to any complications. You may have trouble seeing for several minutes, but this should pass shortly.

Frequently looking at screens can lead to dry eyes. If your eyes are dry and uncomfortable, you can try applying artificial tears to keep your eyes moist.

Normal vision returns within minutes. There haven’t been any reports of vision loss lasting longer than about 10 to 15 minutes.

In theory, it can take up to about 30 minutes for your eyes to fully adjust to the dark after exposure to a bright light. You could have some lingering changes to your vision for up to this amount of time.

Cell phone blindness doesn’t require medical attention, but the symptoms can mimic symptoms of some more serious eye conditions. It’s important to seek prompt medical attention if your vision loss doesn’t return after several minutes or if you have other concerning symptoms, like sudden eye pain.

A doctor will ask you about your symptoms, including what you were doing when your vision loss occurred. If they suspect your vision loss was likely caused by looking at a bright light, you might not need further testing.

Your doctor may order other tests if they suspect an underlying medical problem might be causing your symptoms. Tests you may receive include:

Transient smartphone blindness doesn’t need any particular treatment. Every case reported in medical literature has been fully resolved without complications.

You can prevent cell phone blindness in one eye by making sure that both your eyes are exposed to the light from your phone evenly when looking at your phone in a dark room. If you find that looking at your phone before bed is affecting your sleep, you may want to turn down the brightness on your screen or avoid using your phone in your bedroom altogether.

Although cell phone blindness isn’t linked to any long-term complications, regularly looking at a screen without taking breaks has been linked to eye dryness and eye pain. Chronic dry eyes can lead to long-term discomfort and problems with your cornea.

You can reduce digital eye strain by taking regular breaks where you look away from your device following the 20-20-20 rule. According to this rule, you should look away from your screen every 20 minutes at something that’s 20 feet away for a total of 20 seconds.

Cell phone blindness is temporary, and normal vision usually returns within minutes. There’s no evidence that cell phone blindness leads to eye damage.

If the bright light from your phone is affecting your sleep, you may want to consider avoiding using your phone after you turn off your lights.