In the age of electricity and artificial lighting, our world has become illuminated around the clock. But at what cost? The link between natural light and our internal biological clock, known as the circadian system, is profoundly affected by this modern convenience.

The role of your circadian system harmonizes your hormone production, body temperature, and sleep-wake cycles over a span of 24 hours. This internal rhythm is deeply ingrained in your biology and is controlled by a group of cells called the suprachiasmatic nuclei (SCN).

The circadian system takes its cues from light, particularly the natural light emitted by the sun. This is a biological connection that predates modern technology. When light enters our eyes, it initiates a cascade of signals that travel from the retina to the SCN and then to the pineal gland. This gland, often referred to as our body's "master clock," releases melatonin, the hormone responsible for making us feel sleepy.

Herein lies the issue: artificial light, especially the blue-rich light emitted by screens on televisions, phones, and tablets, can wreak havoc on this finely tuned system. Spending extended periods indoors, which has become a common reality in today's world, exposes you to artificial indoor lighting that suppresses melatonin production. Consequently, your ability to regulate sleep, body temperature, blood pressure, and even glucose levels can suffer.

Research is painting a vivid picture of the consequences of a disrupted circadian system. From the shadows emerge health impairments such as cancer, obesity, diabetes, heart disease, depression, mood and sleep disorders, irritability, decreased physical and mental performance, and diminished productivity. The implications are staggering, emphasizing the profound impact that light has on your overall well-being.

The question then becomes: How do you navigate this delicate balance between light and your biological clock? Here are a few strategies to consider:

Embrace Natural Light: Aim for at least 60 minutes of outdoor light exposure per day. Natural sunlight is a potent regulator of our circadian system.

Leverage Indoor Lighting: When indoors, position yourself near windows to benefit from indirect natural light. Opt for indirect lighting setups that distribute illumination evenly without straining your eyes.

Screen Time Strategy: Limit screen time, especially in the evening. If you need to use screens at night, consider using software like f.lux to adjust your device's color display to match the natural progression of light throughout the day.

Prioritize Sleep Hygiene: Craft a bedtime routine that incorporates winding-down activities, dimming lights, and creating a comfortable sleep environment.

In the grand narrative of your life, light plays a pivotal role. It's a force that shapes your daily rhythms, impacting everything from your health to your mood. By recognizing the significance of the circadian system and making conscious choices about the light you expose yourself to, you can strive for an equilibrium that supports your well-being in this luminous modern world.

Questions for further exploration.

Do you feel sleepy when it gets dark outside?

What is the average length of time between going to sleep and electronic us (TV, phone, computer)?

How many minutes (on average) of daylight a day are you exposed to?