Light as Information: Circadian Hygiene, Red Light, and PEMF

Light is information our biology uses to time hormones, metabolism, recovery and sleep.

In a recent conversation, Shawn Stevenson (author, sleep and performance educator, and host of The Model Health Show) and BON CHARGE wellness-tech founder Andy Mant landed on a simple point: your body is always trying to sync with a 24-hour planet, but modern lighting (and modern habits) constantly "mis-time" that signal. [1]

The Circadian Problem: We Changed the Light, Not the Clock

Human circadian rhythms evolved under a predictable sequence:

• Morning: bright, blue-enriched daylight
• Dusk: warmer, dimmer light
• Night: near-total darkness

The master clock in the brain can't reliably distinguish sunlight from many artificial sources, so bright indoor light after dark can keep the body in "day mode," pushing alertness and impairing sleep onset and quality. [1]

Instead of relying on willpower, use environment design: if you fill your evening with bright overhead LEDs, blue-lit screens, and late meals, you're pushing your circadian system into "daytime mode" and making it work much harder to switch on melatonin and activate parasympathetic recovery. Reverse engineer it.

Blue-Light Blocking: Why Lens Colour Actually Matters

Not surprisingly, "blue-light glasses" aren't all doing the same job. If the goal is to meaningfully cut the blue/green wavelengths most associated with melatonin suppression, you usually need a quality engineered lens that shifts more toward orange/red, not a clear or barely tinted lens. [1]

And it's all about when you use them:

• Evening: stronger blue/green blocking (an evening tool and not an all-day accessory)
• Daytime: prioritize real daylight and balanced light exposure

Red Light Therapy: Dose and Device Quality Matter

Red and near-infrared light are often marketed through beauty, but the evidence base extends beyond aesthetics. A well-cited split-face, randomized, placebo-controlled LED study (76 participants; twice weekly for 4 weeks) found measurable improvements in wrinkles and skin elasticity over the placebo. [2] Lighting design matters because it separates "red-looking light" from effective photobiomodulation.

Red light and near-infrared (NIR) may also support muscle and joint recovery and comfort. A systematic review and meta-analysis of randomized, placebo-controlled trials in knee osteoarthritis (n=1063 across 22 trials) reported statistically significant pain reduction versus placebo at recommended doses. [3]

The Simplest Stack: Light First, Then Tech

The logic is in the sequence:

• Morning: get real outdoor light early.
• Day: take light breaks outside; avoid living in dim indoor "cave light."
• Evening: think of it as "make night look like night" (Andy's simple 321):
  • 3 hours before bed: finish dinner / stop snacking (give digestion a head start).
  • 2 hours before bed: taper fluids if nighttime waking is an issue.
  • 1 hour before bed: screens down (or at least dim, warm, and low-stimulation).
  • Bonus: swap bright overheads for warm, low lamps (your eyes shouldn't feel like it's midday at 9pm).
• Keep timing consistent enough: similar wake time and meal timing most days so your body isn't constantly guessing.
• Reduce the late-night stimulants: late meals + bright light + late scrolling = "daytime mode" signals.

Then use tools as supportive layers:

• Blue light blocking glasses can help protect the evening "darkness" signal.
• Red light therapy can be a more circadian-friendly evening light environment and a recovery/skin routine.
• PEMF can be an optional wind-down / recovery add-on to add to the circadian foundation.

References

1. The Model Health Show (Feat. Shawn Stevenson and Andy Mant). Full episode (transcript). 2026.
2. Lee, S. Y. et al. A prospective, randomized, placebo-controlled, double-blinded, and split-face clinical study on LED phototherapy for skin rejuvenation. J. Photochem. Photobiol. B 88, 51–67 (2007).
3. Stausholm, M. B. et al. Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials. BMJ Open 9, e031142 (2019).