The spectrum of visible light, the wavelength of the light

Light is visible (electromagnetic) radiation capable of producing directly in humans and animals visual sensations from which vision results. Artificial light sources are mostly electric sources, while the light they produce is basically a non-electric quantity, expressed in terms of photometric quantities and laws.

Visible radiation is assumed to contain electromagnetic waves in the spectrum in a very narrow range, from 380 to 780 nm. This is the range that our eye perceives, but animals can register radiation of different lengths.

In the spectrum of visible light there are ranges with different wavelengths that the human eye perceives as different colors, e.g .:

• range with a wavelength from 380 nm to 436 nm - violet
• the range with a wavelength from 436 nm to 495 nm - blue
• the range with a wavelength from 495 nm to 566 nm - green
• the range with a wavelength from 566 nm to 589 nm - yellow
• range with a wavelength from 589 nm to 627 nm - orange
• wavelength range from 627 nm to 780 nm - red.

We see best in the middle of the visible spectrum and worst at the ends of the range.