Lying in bed, scrolling your phone — it really is the best part of the day. But it is also the most dangerous thing you do to your eyes every single night.
Surveys have found that more than 80% of people habitually use their phones before sleep. And even when they feel sleepy, more than 80% of them stubbornly keep scrolling [1].
Your spirit can handle it. Your eyes cannot.
When your energy runs out, you can recharge. When your eyes are damaged, they do not bounce back so easily.
Sin One: The Position — Lying Flat, Lying Prone
The first thing to criticize is the "lying down."
Under the covers, almost everyone curls up with the phone held in front of their face. Have you ever thought about how close your eyes are to the screen? If this were childhood TV-watching, your parents would have thrown a stool at you.
Sitting upright during the day, your eyes sit about 30 to 40 centimeters from the phone. Lying in bed — especially for nearsighted people who have taken off their glasses — whether flat on your back, on your stomach, or on your side, your eyes end up only 20 centimeters or even closer from the screen.
The closer the screen, the more focusing effort your eyes must exert, and the more pressure they absorb. All of it adds up to faster eye fatigue.
This fatigue is not the fatigue of running an 800-meter race. It is not something a short rest cures. It belongs to a condition called computer vision syndrome: what you feel is tired eyes, but what you cannot feel are the many visual dysfunctions quietly accumulating — slower focusing, and eyes that easily blur on near objects.
Side-lying deserves special criticism.
When you lie on your side, the two eyes sit at different distances from the screen, and one eye may be pressed against the pillow and closed — you end up watching with one eye only. Your eyes tire faster, and the vision in that single eye can decline.
But do you care about tired eyes? You only care whether the phone is fun.
Sin Two: The Lights Are Off
Your pupil size tracks ambient light: it shrinks in bright light and dilates in dim light.
When you lie in the dark scrolling, the room is pitch black, so your pupils dilate to let in more light — but the phone screen is bright, so your pupils constrict to let in less. Your pupil cannot dilate and constrict at the same time. It just keeps adjusting, over and over. It is exhausting.
And do you care about tired eyes? You only care whether the phone is fun.
Beyond fatigue, playing with your phone in dim light causes subtle changes inside the eye. It can disturb the balance of fluid moving in and out of the eyeball, and can even push intraocular pressure upward. If you are born strongly hyperopic, or have structural eye abnormalities, or a family history of glaucoma, this can trigger acute angle-closure glaucoma — a disease that can cause blindness.
This beautiful world — do you not want to keep looking at it?
Sin Three: The Sessions Are Too Long
Why did your parents never allow an entire afternoon of TV? Because your eyes get dry! They get hurt!
Every time you blink, tears spread evenly across the cornea, keeping it moist and working properly. But that tear film only lasts so long before it breaks. That is why you blink 10 to 20 times every minute — to keep the ocular surface from drying out.
When you are so absorbed in your phone that you cannot look away, your blink rate drops (count how often someone blinks while playing with their phone — you will see). Without the tear film's protection, you may feel stinging and dryness. Over time, tear secretion becomes abnormal, tear film stability drops, dry eye sets in, and eye fatigue gets worse.
But you… let's not even go there.
Cry! Crying keeps your eyes moist! 丨giphy
Eye-Friendly Ways to Scroll in Bed
Now you care about tired eyes — but you cannot bear to give up the joy of scrolling before sleep. So here are some suggestions for scrolling in bed in a relatively eye-friendly way.
Turn on a lamp!
Scrolling with the lights off is nothing but harm to your eyes. The ceiling light is too bright and disturbs sleep, so…
