The Bright Truth: Your Brain’s Secret Relationship with Light

Hey Brain Warriors,

Two weeks ago we broke down circadian rhythms and why ignoring your body clock costs you in energy, mood, and performance. Now, let’s zoom into the primary driver of that clock: light. Because, you might not know this, it behaves like a neuro-active substance, and we’re dosing ourselves all day, often badly.

How Light Hacks Your Clock

• Specialised retinal ganglion cells (ipRGCs), containing melanopsin, send light signals directly to your brain’s master clock (the SCN).
• Light exposure in the morning advances your clock, making you feel alert earlier; in the evening, especially blue-rich light, it delays sleep, suppresses melatonin, and keeps your system wired .

Blue Light: The Double-Edged Sword

• During the day, blue-enriched light boosts alertness, mood, memory, and working speed.
• At night, however, it’s a major disruptor: even dim levels from screens drastically suppress melatonin, more than warmer tones, keeping you awake and groggy.

Modern Lights vs. Human Evolution

• Our brains evolved under natural sunlight, this is why lighting affects everything from mood to metabolism.
• Studies show even low artificial light can rewind sleep drivers. Long-term exposure to unnatural lighting links to disrupted sleep, metabolism, mental health risks, and even chronic disease.

Smart Light Habits for Everyday Performance

As light behaves like a drug for our biology, timing is the dosage. Here’s how to use it wisely:

Morning: Get outside within 30 minutes of waking, no sunglasses, just real daylight on your eyeballs (don’t stare at the sun, obviously). This tells your brain, “It’s go time!” and kickstarts your natural rhythm for the day.

Daytime: Keep your workspace bright. Natural light is ideal, but a bright, cool (bluish) light will do. This helps you stay focused, alert, and less tempted to nap at 2 pm while pretending to read an email.

Evening: Start dimming the lights about two hours before bed. Think warm tones, lamps, or even red lights if you want to go full biohacker (I use bulbs with no blue light and red-lights in the bathrooms - mega useful if you need to use them during the night). Avoid ceiling spotlights that scream “interrogation room.”

Night: Your bedroom should be as close as possible to pitch black. No blinking chargers (why would you charge anything in your bedroom anyways?), no hallway light creeping in, no TV glow. Your brain needs total darkness to go deep into sleep and stay there.

This routine costs nothing, takes zero effort, and your brain will love you for it.

5. Real Gains, Real Results

This isn’t just theory. Here's what happens when people actually use light wisely:

Older adults who got blue light in the morning slept better and hit deep sleep faster. Translation: fewer 3am fridge raids and more restful nights.

People with Alzheimer’s saw better mood and sleep with simple light therapy. No fancy drugs, just brighter mornings and dimmer evenings.

Night shift workers (a.k.a. human time travelers) reported fewer sleep issues when their workspaces had blue-enriched lighting at night. Not ideal, but better than battling biology in the dark.

Even back in the 60s, researchers threw people into bunkers (yes, literal underground bunkers) with no clocks or windows......and guess what? Their body clocks drifted. That’s how powerful light is.

Modern studies are just confirming what nature already knew: if you respect light, it pays you back in focus, energy, mood, and real performance.

✅ What You Can Do This Week

1. Sleep audit: Track light exposure after 7 pm. Too much screen time? Adjust.
2. Morning sunshine: Make it a habit, even 5 minutes works wonders.
3. Swap bulbs: Switch to warm LED or smart bulbs with night mode after sunset.

Final Thought

Light isn’t just something that helps you see, it’s something that helps you function. It’s the first input your brain uses to set the tone for everything: focus, mood, energy, digestion, and yes… deep, restorative sleep.

Mess with your light, and you mess with your rhythm. Master your light, and your brain starts performing like it wants to —> sharp, calm, and clear.

On that note, I’m opening up spots for my group coaching program, Deep Sleep Reset, starting the second week of September. If your sleep has been inconsistent, light-disrupted, or just not doing the job it should, this reset is for you. It’s designed to help you reboot your sleep, naturally and sustainably, by aligning biology with behaviour.

⚠️ I’m keeping the group small to make it personal and effective, so seats are limited.

Click the banner or message me if you want in, and we will discuss the details.

Until next time, keep those neurones firing.

Thierry

PS: What changes will you make this week? Share your “light experiments” with us, let’s build the science-backed routine your brain craves.