Luminous flux is known as the power of light perceived by the eye. The SI unit of luminous flux is known as lumen where one lumen is the amount of luminous flux emitted from a directional unit point source through a unit solid angle.
Since the human eye can see only the visible spectrum of light which is perceived in the form of luminous flux and thus lumen.
Lumen may be defined as the S.I. unit of the luminous flux and denoted by the ln. The human eye can only see the wavelength of the lights lies in the visible spectrum.
The power of light perceived by the eye is known as Luminous flux . One lumen may be defined as the amount of luminous flux emitted from a directional unit point source through the unit solid angle.
