Optical brighteners VS fluorescent dyes

The common point is that both can emit fluorescence.

The difference is that optical brightener absorbs invisible ultraviolet light and emits visible fluorescence with shorter wavelengths; while fluorescent dyes absorb visible light and emits visible fluorescence with longer wavelengths.

	In Common	Absorb	Emit
Fluorescent Brightener	Emit fluorescent	Invisible ultraviolet light	Visible fluorescence with shorter wavelengths
Fluorescent Dyes	Emit fluorescent	Visible light	Visible fluorescence with longer wavelengths