In 1700 a typical Briton consumed 580 lumen-hours in the course of a year, from candles, wood and oil.
But to sleep with the blinds open, I'd have to buy a rifle and shoot out the confounded sodium vapor streetlight that, but for those blessed pecan strips, throws a 9,500-lumen glare over the room.
The light perceived by the human eye is measured in units called lumen-hours. This is about the amount produced by burning a candle for an hour.
