Light Bulb brightness and illumination

The light that is percieved by the human eye is called the luminous flux. The measurement of that light is the lumen (lm). Simply put: lumens are the measure of the amount of light we see. This 'brightness' is now required to be listed on light bulb packaging. Lower numbers are duller and higher numbers are brighter.

When purchasing light bulbs the best measure to determine suitability is the lumen. Is is recommended that you determine the lumens required and pick the lightbulbs that require the fewest watts. Fewer watts means lower electricity bills. That is where LEDs really shine. LEDs have a lumen to watts rating that far surpass incandescent bulbs and even have better ratings that compact florescent bulbs (CFLs)! This means that an LED light will cost you less in electricity and still shine bright.

The brightness of a light is measured in lumens because the sensitivity of human eye differs according to the wavelength of the particular light source. Lumens is a measurement that takes the human factor into consideration.