If you're spending your days indoors—working, parenting, or just getting through another Norwegian winter—you might be missing out on one of the simplest biohacks available: opening a window.

I talk a lot about red light therapy, blue light, and circadian biology, but this article is about something even more basic—natural light through an open window. It's free, immediate, and surprisingly effective. Here's what you gain when you let unfiltered daylight in.

Natural Light vs Indoor Light in Norway

In Norway, daylight hours shrink dramatically in winter and early spring. Most indoor lights fail to deliver the full spectrum of light your body evolved with. Even energy-efficient LEDs and so-called daylight bulbs are missing key wavelengths which can have negative impacts on various aspects of your health during the day.

With the window open, you get full access to:

• Blue light (460–490 nm)
• Green and red (500–700 nm)
• Near-infrared (750–850 nm)
• A small amount of UV-A (380–400 nm)

With the window closed, you lose a significant amount of this spectrum—especially UV light and near-infrared as well as reducing the intensity and changing the balance of light. Changing this balance changes the effectiveness of this light on specific actions on the body. Below is a simple and short explanation of why a window being open might be a positive addition to your daily routine this spring and summer:

1. Blue Light Supports Circadian Health

During the day, especially in the morning, blue light exposure:

• Signals your brain that it’s daytime
• Boosts cortisol and dopamine
• Improves mood and alertness

In Norway’s dark season, this becomes critical. Blue light through an open window acts like free light therapy.

2. Balancing Blue Light with Red and Infrared

Blue light is vital for waking you up and syncing your circadian rhythm, but it needs balance with red and near-infrared light. An open window provides some blue light, yet glass filters out much of the red (500–700 nm) and near-infrared (750–850 nm) that your cells crave for energy and recovery. Indoor artificial lights—rich in blue—amplify this imbalance, leaving you overexposed to blue without the counterbalance of warmer wavelengths.

At Home Light Therapy, we know balance is key. Too much blue without red and infrared can strain your eyes and disrupt sleep over time. Pair your window habit with our red light therapy solutions to restore the full spectrum indoors.

3. Balancing Hormones with Morning Light

Morning daylight exposure helps regulate melatonin and cortisol levels. A strong circadian rhythm leads to deeper sleep and improved energy.

4. Serotonin and Mood Regulation

Natural light supports serotonin production. In Norway, where Seasonal Affective Disorder is common, early daylight exposure helps stabilize your mood and increase resilience.

5. Eye Health and Visual Development

Exposure to full-spectrum light reduces the risk of myopia. Kids and adults both benefit from working near an open window.

6. Near-Infrared and Mitochondrial Support

Near-infrared (750–850 nm) penetrates tissues and enhances cellular energy production—similar to red light therapy. But glass blocks this wavelength. An open window restores it. Below is an image of the spectrum of light that shows higher levels of red and infrared through and open window.

Beneath that you can see the closed window. The blue doesn't really change, but the levels of red and infrared drop away far more quickly, you no longer have the balance. If you then add a blue backlit screen, you further increase the blue and reduce the red/infrared as a percentage of total spectrum

7. Brain Function and Productivity

Daylight supports brain performance, memory, and learning. If you work from home in Norway, keep the window open during peak light hours to increase focus.

Simple Daily Habit

Open the window while you work, eat breakfast, stretch, homeschool (as I do) or work from home. It’s a no-cost upgrade to your light environment—and your biology.

Take It Further with Light Therapy

I offer red light therapy panels, blue light blockers, and circadian lighting designed to restore optimal light indoors. Start with your window—upgrade with Home Light Therapy.