it's probably that you're not supposed

to use any screens before bed.

And if you're anything like me, you've

probably ignored that advice. Because,

Come on.

Even sleep experts can't resist.

Do you use your phone before bed?

Yes, just to catch up on my calendar and email,

it's always less than 30 minutes for me.

That's Rohan Nagare, a sleep researcher

who's coauthored several papers on the topic.

As a chronic screen's before bed guy myself,

I went into our conversation

wanting to know if there is any way

that we could keep using our phones at night

without completely wrecking our sleep schedules.

Turns out science suggests

our sleep schedule is way more malleable

than we might think.

Before we dive into the science,

let's first get a quick review on how our body responds

to natural light like the sun.

and the lack thereof.

You've probably noticed

that at night you naturally start feeling sleepy.

This is because your body produces melatonin,

a hormone that plays a huge role in sleep.

melatonin is not just, any other hormone.

it's kind of an internal timekeeper.

As the sun rises

and you get exposed to its bright light, your body suppresses

the production of melatonin, helping you feel awake and alert.

But sun exposure isn't the only factor here.

The color temperature of light also changes throughout the day.

Daylight exists at roughly 5600 Kelvin, which leans quite blue.

A sunset leans much warmer in the 3000 Kelvin range.

This natural color

shift, combined with the decreasing brightness,

tells our body to kick

start the production of melatonin, which makes us feel sleepy.

Natural light makes things simple on our bodies.

But once you start adding artificial light into the mix,

things get a little more complicated.

Especially when we're staring at these all night.

Phone screens at their baseline

have a color temperature of 5600 Kelvin, or daylight.

So when you hear that

using your phone before bed is bad for you.

This is the commonly cited reason as to why.

The phone's artificial daylight, aka

blue light, suppresses the production of melatonin,

disrupting our feelings of sleepiness.

Now, You might be wondering, don't phones

have a built in feature

that's intended to counteract this blue light?

They do.

It's called night mode or night shift.

But does it actually work?

Well, In 2019, Rohan

coauthored a study that tried to answer that question.

It's a very smart feature,

The idea is right, they're trying to manipulate

a lighting characteristic, which is the spectrum,

to reduce the circadian effectiveness.

The study looked at two modes of warm shift

high CCT which meant that the screen

colors were intensely shifted to the warmer end of the spectrum

and low CCT

which meant that there was only a slight warm shift.

Both modes suppressed

melatonin, the sleepy hormone, and the results showed

that there wasn't a meaningful difference between the two.

And while that makes it sound like Night Shift doesn't work,

it's actually a lot more complicated than that.

Spectrum is just one aspect.

Distribution duration, timing and amount needs to be considered

So if you're using phone in the night,

I wouldn't be too concerned if it's 20 minutes, 30 minutes.

But if it's beyond that,

if you're going to watch a movie every night

or like three episodes of a Netflix show,

you know, then it accumulates a pretty good circadian dose,

which can keep delaying you every day.

What Rohan is saying here

is that limiting the time you spend on

your phone can also make a difference,

and warm shift is just part of the solution.

When we use our phones

were staring directly into a light source

and how much light falls onto a certain area

like our eyes, usually measured.

in lux is dramatically impacted by our closeness to the device.

In fact, you experience a closer light source as four times

more powerful than that

same light source twice the distance away from you.

if you're going to get 1000 lux at your eye,

it honestly doesn't matter

if it's a warm source

or a cool source, that's too high and you're already

saturating your circadian system.

So we know that limiting screen duration,

shifting the colors warmer,

and lowering the brightness all helps.

But Rohan also let me in on an interesting biological hack

that can make a huge difference

in how impactful your late night screen time is.

what you really want is a contrast

between how much light you get immediately after you wake up

for an hour or two, and immediately

before you sleep 1 or 2 hours.

It's possible to trick your circadian system and say, okay,

if I'm going to blast my screen brightness

and bump up my 50 lux to 200 lux in the evening,

I can just counter that

by getting 800 lux in the morning.

So that's the beauty of your circadian system.

You can use its own mechanisms against it.

So basically, if you go for a sunny walk in the morning,

you could potentially offset the amount of circadian disruption

you're experiencing from your phone.

At the end of the day.

Body hacks aside,

the thing that I realized as I was researching

this story is that

there are so many more factors that impact our sleep

besides just the blue light that comes out of our phones.

And we haven't even touched on them all yet.

Like what you do on your phone,

whether it be doom-scrolling or watching a scary movie,

all that can be just as stimulating

and disruptive to your sleep

as the amount of light that you're taking in.

At the end of the day, figuring out

how to have a healthier relationship with our devices

is a big step

in figuring out how to have a healthy

relationship with our sleep.

Thank you so much for watching this episode of Even Better.

At Vox, We're always looking for new tools to analyze

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