Lumen (unit)
The lumen (symbol: lm) is the SI derived unit for brightness. It is defined as 1 candela times 1 steradian.
One lumen is about a twelfth the brightness of a candle, so a candle has a brightness of around 12 lumens.
File:V-LIGHT A314.JPG
It says on the package that this lightbulb makes 470 lumens.