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Term: Visible spectrum

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Term: Visible spectrum

The band of electromagnetic radiation that human eyes can detect. This ranges from wavelengths of approximately 400 to approximately 700 nanometers (nm). Normal human vision responds slightly beyond this range to both shorter and longer wavelength radiation, but with very little sensitivity. Maximum sensitivity of the human vision in bright-light conditions is approximately 555 nm, corresponding to the perception of green. Visual sensitivity to wavelengths is dependent on luminance levels or levels of brightness, and is described as scotopic (dark-adapted) and photopic (light-adapted) sensitivities. A less common term is mesopic sensitivity, falling between dark and light-adapted sensitivity. The term "light" is equivalent in meaning to "visible spectrum." The section of the band of electromagnetic radiation with a wavelength shorter than that of visible light is termed ultraviolet and the section with wavelengths longer than that of visible light is termed infrared.
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