Majoring in the Minors- Week 2
Light Exposure & The Biology of Better Days
Last week, in the first installment of Majoring in the Minors, we talked about heat and cold therapy- simple tools that create controlled discomfort, strengthen resilience, and amplify recovery. This week, we’re shifting from physical temperature to something even more foundational: light. If heat and cold challenge the body intentionally, light is the signal that tells the body what time it is, and therefore, how it should function. It’s a silent conductor running the entire orchestra of your biology. Most people never think about it. But once you start paying attention, you realize just how much it controls your energy, your mood, your focus, and your sleep.
Light is the first input your brain cares about. It sets your circadian rhythm, your internal 24-hour clock, and tells your body when to wake, when to focus, when to repair, and when to rest. This is why shifting your relationship with light, even in small ways, can have a profound effect on how you feel. We tend to think of sleep as a nighttime issue, but the truth is that good sleep begins in the morning, with the first light you expose yourself to.
When you step outside into natural morning light, a few powerful things happen. Your cortisol rises in a healthy, stabilizing way- not as a stress response, but as a wake-up signal. This is called the cortisol awakening response, and a strong one keeps your energy steady throughout the day. Morning light also starts your internal countdown to melatonin, the hormone that helps you fall asleep. Most people don't realize this: melatonin isn’t just released at night; it’s scheduled in the morning. That first dose of sunlight triggers the timer that tells your brain when, later, it should wind down.
But just as light can anchor your day, the wrong kind of light can disrupt it. Bright artificial light at night- especially LEDs, phone screens, tablets, TVs, and overhead bulbs- tells your brain it’s still daytime. The wavelength that suppresses melatonin most strongly is blue light, especially in the 460–480 nm range. We’re not meant to be staring at electric daylight after sunset. When melatonin is delayed, sleep becomes shallow, fragmented, and less restorative. Because melatonin is also a major antioxidant and repair signal for the body, disrupted timing affects recovery, immune function, and metabolic health.
Some people are even more sensitive to artificial light than others. Fluorescent and many LED lights have flicker patterns- rapid on/off cycles that the brain still has to process even if our eyes don’t consciously detect them. And here’s a detail most people never hear: phones often have a higher flicker rate than TVs or computers. The brightness on many smartphones is controlled by a fast flicker called PWM (pulse-width modulation), and while you can’t see it, your nervous system definitely feels it. For people sensitive to light, this can cause eye strain, headaches, anxiety, fogginess, or a sense of dissociation. It’s not that anything is “wrong” with them, their brain is simply working harder to stabilize the visual input.
The good news is that flicker sensitivity has real, practical solutions. One option is switching to high-quality LED bulbs with low flicker percentage, which are becoming more widely available as lighting companies respond to research in this area. Using lamps with diffusers can soften both brightness and flicker intensity. On screens, enabling options like “reduce white point,” “anti-flicker,” “DC dimming,” or low-brightness-without-PWM modes can significantly ease neurological strain. Some people also find relief by adjusting screen contrast and sharpness or adding matte screen filters, which calm the visual cortex. Blue light blocking glasses can help as well, not because they stop flicker, but because they reduce stimulating wavelengths, making the brain’s job easier. The goal isn’t to eliminate artificial light entirely- that’s impossible- but to reduce the neurological load in environments where flicker is unavoidable.
There’s also the restorative side of light. Red and near-infrared wavelengths have been shown to influence mitochondrial function- particularly by interacting with cytochrome c oxidase, an enzyme involved in ATP (energy) production. This doesn’t make red light therapy a miracle cure, but it does help explain why morning sunlight, which naturally contains red and infrared light, feels grounding and energizing. Different wavelengths send different signals.
This brings me to one of the simplest personal changes I’ve made. I like watching TV and sports at night to unwind- it’s how I relax. But because screen light can delay melatonin, I started wearing blue light blocking glasses in the evening. It’s not complicated or expensive, but it helps filter the wavelengths that keep the brain alert. On nights I wear them, falling asleep is easier, my mind slows down faster, and I wake up feeling more restored. It’s a small habit that fits my real life- and that’s the whole point.
With all this science, you might think light management requires a complicated routine. It doesn’t. My biggest improvements came from two simple habits: stepping outside in the morning for 2–5 minutes of natural sunlight, even on cloudy days, and reducing artificial light at night by turning off bright overhead lights and switching to warm, softer lamps. Adding blue blockers gave me a nighttime buffer without forcing me to sacrifice things I enjoy, like watching sports or relaxing with a show.
These changes are small, but the outcomes aren’t. Better sleep, steadier energy, improved mood, sharper focus- all from using light the way our biology expects us to. For most of human history, light came from the sun and fire. Now it comes from screens, LEDs, and fluorescent tubes. Our bodies simply haven’t had time to adapt to this shift, and many of the symptoms people struggle with- insomnia, fatigue, brain fog, inconsistent energy- often stem from disrupted circadian biology.
This is the heart of Majoring in the Minors. Not trying to hack our biology, but learning how to work with it. Understanding the signals our body pays attention to, and giving it the input it was designed for. Light is the most basic input of all, and yet, when you get it right, it feels like a cheat code.
Next week, we’re diving into clean air, clean water, and clean environments- how the quality of what you breathe and drink affects inflammation, energy, recovery, and overall well-being. These aren’t glamorous topics, but they’re foundational. Most people focus on workouts and macros, but overlook the very air they inhale and the water they drink every day. And just like light, these inputs shape far more of our health than we realize.
