Wavelength (Nanometers)
Quick definition
Wavelength is the specific color of light, measured in nanometers, which influences how it behaves in the skin.
The Science
Different wavelengths produce different biological effects. Blue light is commonly used for acne-focused devices, red light for anti-ageing support, and near-infrared for deeper tissue support.
Why it matters for your skin
You want brands to state exact wavelengths rather than vague claims about red light or multi-spectrum technology.