If you could have any superpower, what would it be?

My answer often surprises people.

It's not "invisibility" or "flying."

My answer is something much more practical:

The ability to fall asleep immediately anywhere, anytime.

This week I will explore how you can leverage light to fall asleep faster

For the next few weeks, I will dive into hacks to get to sleep faster.

This week, I will focus on how light affects our sleep.

Table of Contents

1. What makes us fall asleep?

2. A common theme: light

3. 3 action items to exploit light for better sleep

4. Why should I avoid overhead lights at night?

5. Summary

What Makes Us Fall Asleep?

There are three main biological factors that cause us to fall asleep at night:

1) Circadian Rhythm - our biological, 24-hour clock, calibrated mainly by light exposure

2) Sleep Pressure - the buildup of adenosine, a molecular byproduct of our body producing energy

3) Melatonin - a hormone produced in response to darkness signaling to our body it's time for sleep

A Common Theme: Light

Notice a common theme?

Both our circadian rhythm and melatonin levels are greatly affected by light and darkness.

And here's the twist:

Early in day, it takes lots of sunlight to wake your body up.

Late in day, it takes very little light to damage your ability to sleep.

This is because very little light will significantly lower melatonin levels, causing your body to be less tired.

Sleep Hack: 3 Action Items to Exploit Light for Better Sleep

To fast track your way to falling asleep faster, follow this three-step action plan after the sun sets:

Stay away or dim all artificial lights

1) Turn off all bright overhead lights, instead use lamps or, preferably, candlelight/moonlight

2) Use the least light possible that still allows you to perform your necessary tasks

3) Use a sleep mask or blackout blinds to keep a very dark sleep environment

Why Should I Avoid Overhead Lights at Night?

There's a reason our body is so responsive to sunlight.

It's because sunlight enters our eyes from above.

Why does this matter?

Here's why.

Our body processes light through the eyes.

And, the eye cells that regulate circadian rhythm are located in the bottom half of our eyes.

Counterintuitively, these bottom half cells view the upper half of our visual field.

This means that our circadian rhythm is mainly influenced by our upper visual field.

This is why overhead lights, like sunlight, are so effective at both waking us up and keeping us awake.

And, why you should avoid overhead lights during the night at all costs.

Summary

Light exposure heavily influences circadian rhythm and melatonin levels.

Thus, it takes little light to ruin melatonin levels at night.

But, higher melatonin levels help us fall asleep faster.

So, here's what you should do.

Action Items:

Take these 4 steps to fall asleep faster:

1) Turn off all overhead lights after sunset

2) Use the bare minimum artificial light needed to carry out nighttime tasks

3) If you have to use light, place them low and use primarily candlelight or, ideally, moonlight

4) Blackout your bedroom with a sleep mask or blackout curtains