Design
Design vs. use.
How they're designed
Some company wants to make a new model of alarm clock for sale to the hotel market. After months of work, a team of engineers enters a brightly lit conference room. “Ok, let's test it.” “Is it plugged in?” “Yes.” “Ok, turn out the lights.” … “See, I don't think that's bright enough.” “Ok, let's make it brighter.” “Great meeting, everyone. On to production!”
How they're used
Roll over after six hours of sleep in more-or-less darkness. Open your eyes, pupils the size of saucers, and stare into the blazing light of a thousand screaming suns. “My eyes! My eyes!” Next day, figure out how much furniture you have to move to unplug the [expletive deleted –ed] thing.