Lux is a measurement of the overall intensity of light within an environment for any given area or distance from the source or lux is the amount of light in an environments perceived by the human eye. Quality of light in workplace, schools and public buildings affect the quantity and quality of performance in workers and students.
In other words, the lux is a unit of measurement of brightness, or more accurately, illuminance. The illumination is how level of luminous flux is falling on a surface area. The luminous flux is visible component that is defined in radiant flux (light power) divided by relative sensitivity of human eyes over the visible spectrum. This means the Lux is well fit to light level from sense of human eyes. Lux is ultimately derives from the candela, the standard unit of measurement for the power of light.