Near Infrared Light Devices: Wavelength, Distance and Dose Basics
Quick answer: Near infrared light is invisible and sits around 850nm on most home devices. Intensity falls as you move away from the device, and dose equals irradiance multiplied by time. Use the manual for session length and the spec sheet for irradiance.
Near infrared shows up on almost every panel and wearable spec sheet. This guide explains the terms and the arithmetic.
Key terms
| Term | Meaning |
|---|---|
| Wavelength | Color of light in nanometers; 850nm is near infrared |
| Irradiance | Power reaching a surface, in mW/cm2 |
| Dose | Energy delivered, in J/cm2 |
Dose formula: J/cm2 = mW/cm2 x seconds / 1000.
Worked example
Example numbers for arithmetic only: at 80 mW/cm2 for 300 seconds, 80 x 300 / 1000 = 24 J/cm2. Change the distance and the irradiance changes, so the dose changes with it. Our dose calculation guide goes deeper.
Measured values for AWA panels
The irradiance specs post lists measured values at each distance for the FX300 and the FX500. For wearable use, the belt is a hands free option.
Common mistakes
- Comparing irradiance numbers taken at different distances.
- Picking a device only because it lists the biggest number.
- Forgetting that near infrared is invisible, so eye protection still matters.
Frequently asked questions
What is the difference between red and near infrared?
They are different wavelengths. See 660nm vs 850nm.
Can I see near infrared light?
No. Some LEDs show a faint red glow, but the light itself is invisible.
How long should a session run?
Follow your manual. See our session length guide.
Browse the panels collection. This guide is educational and is not intended to diagnose or replace clinician advice.
How we create this guide: We write from product specs and review each claim against our editorial standards.
Updated October 2026.
