Dr. Matt Walker

Whereas if the lights were blazing, you've got your phone, television's on, lots of stimulation, you're probably going to think 10.30, no, I could probably push through for at least another hour.

So try to dissipate that light.

And then if you need to, wear an eye mask, blackout curtains, always good as well.

But we need that darkness at night because when you give the brain the signal of darkness, it releases effectively a brake pedal.

That brake pedal has normally been applied by way of light on the release of that spigot of melatonin.

And when you take the brake pedal off, it starts pumping out into the brain.

You can also then, of course, probably reverse engineer this trick in the morning.

And this is another component of why you've been, I think, such a wonderful advocate for light in the morning.

It does many things, but one of the things that it does

is reapply that brake on melatonin and therefore you lose the signal to your brain of darkness.

That's what melatonin in some ways is doing.

We often call it the hormone of darkness or the vampire hormone.

Not necessarily because it makes you look longingly at people's necklines and want to bite in, which is great if you're into that, but it's really simply about it's releasing melatonin, which tells the brain, my goodness, it's nighttime.

But if you've got bright light on, you come from your office, you're driving home, so you've got artificial light during the day, which is probably not strong enough to stimulate you and bring you awake.

You come home and you've got again, bright light

but it's still strong enough now to prevent the release of melatonin, you start to shift in your timing and you may have problems with your sleep.

So that's the second piece of advice.

I would love to ask you about that morning light too and the alertness benefits.

I'm, as a sleep researcher, more focused on the evening component of light and decreasing it, but you've done a great job.

I don't know if there's anything...