Quick answer: The most important red light terms to know are wavelength (the color of light in nanometers), red light (around 660nm, visible, surface-level), near-infrared (around 850nm, invisible, reaches deeper), irradiance (light energy reaching a surface), LED (the light source), and photobiomodulation (the scientific name for the research field). Knowing these makes spec sheets easy to read.
Shopping for red light is much simpler once you know the vocabulary. Here is a quick, plain-English glossary.
Core terms
Wavelength (nm): the precise color of light, measured in nanometers. It determines whether light is visible and roughly how deep it reaches.
Red light (around 630 to 660nm): visible red light absorbed at and near the skin surface; popular for skincare devices.
Near-infrared light or NIR (around 810 to 850nm): invisible light that reaches a little deeper than red; common in body devices for soothing warmth and comfort.
Blue light (around 450nm): a visible wavelength sometimes included in face devices, associated in skincare with the look of clearer skin.
Dual-wavelength: a device that combines two wavelengths (commonly 660nm and 850nm) to cover surface and deeper layers in one session.
Spec-sheet terms
LED (light-emitting diode): the small, energy-efficient light source used in these devices.
LED count and chip count: how many emitters a device has. Some use multi-chip LEDs (for example 3-in-1), so chip counts can be higher than LED counts. More can mean broader coverage.
Irradiance (mW/cm2): how much light energy reaches a given surface area. With wearables, the light is delivered right at the skin.
Power or wattage (W): how much electricity the device uses. Higher wattage is not automatically better for you.
Timer: a built-in setting that ends a session automatically, handy for effortless, consistent use.
Science and category terms
Photobiomodulation (PBM): the scientific name for the study of how cells respond to red and near-infrared light. It is an active, ongoing research field.
Non-invasive: used externally, with no needles, incisions, or downtime.
EMF: electromagnetic field; some devices advertise low-EMF designs.
Key takeaways
- Wavelength (nm) is the most useful spec to understand.
- 660nm is red and surface-level; 850nm is near-infrared and deeper.
- Irradiance, power, and LED count describe intensity and coverage.
- Photobiomodulation is the scientific research field.
Frequently asked questions
What does nm mean in red light therapy?
Nanometers measure wavelength, essentially the color of the light, which indicates whether it is visible and roughly how deep it reaches.
What is photobiomodulation?
It is the scientific term for the study of how cells respond to red and near-infrared light, and it is an active research area.
What is the difference between red and near-infrared?
Red light (around 660nm) is visible and surface-level; near-infrared (around 850nm) is invisible and reaches a bit deeper.
What is irradiance?
It is the amount of light energy reaching a surface, often shown as mW/cm2. Wearables deliver light right at the skin.
What does dual-wavelength mean?
A device that uses two wavelengths at once, commonly 660nm and 850nm, to cover both surface and deeper layers.
Explore red light wellness at Vyalight
Put these terms to use on any product Specifications tab in our best sellers, face masks, and belts.
Disclaimer: Vyalight products are consumer wellness devices, not medical devices. They are not intended to diagnose, treat, cure, or prevent any disease or health condition. This content is for general informational and wellness purposes only and is not medical advice. Individual experiences vary. Consult a qualified healthcare professional with any health questions.
