Optical spectrum

[[Image:spectrum4websiteEval.png|centre|approximation to the white light spectrum dispersed via an EdmundScientific Spectroscope or a 4x8 sheet of

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diffraction grating.]]

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The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. There are no exact bounds to the optical spectrum: a typical human eye will respond to wavelengths from 400 to 700 nm, although some people may be able to perceive wavelengths from 380 to 780 nm. A light-adapted eye typically has its maximum sensitivity at around 555 nm, in the yellow region of the optical spectrum.

Related Topics:
Electromagnetic spectrum - Visible - Human - Eye - Wavelength - 400 to 700 nm - Nm - Light - Nm - Yellow

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Wavelengths visible to the eye are defined by the spectral range of the "optical window", the region of the electromagnetic spectrum which passes largely unattenuated through the Earth's atmosphere (although blue light is scattered more than red light, which is the reason the sky is blue). Electromagnetic radiation outside the optical wavelength range, or other transmission windows, is almost entirely absorbed by the atmosphere.

Related Topics:
Optical window - Earth - Atmosphere - Transmission window

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The eyes of many species perceive wavelengths different than the spectrum visible to the human eye. For example, many insects, such as bees, can see light in the ultraviolet, which is useful for finding nectar in flowers.

Related Topics:
Insect - Bee - Ultraviolet - Nectar - Flower

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