Visible Light Definition

This is a linear representation of the visible spectrum of light.
This is a linear representation of the visible spectrum of light, which extends roughly from 400-700 nm wavelength. Gringer, public domain

Definition: Visible light is a range of electromagnetic radiation that can be detected by the human eye. The wavelengths associated with this range are 380 nm to 750 nm. (1 nm = 10-9 m)