Object Lessons is a series of short, beautifully designed books about the hidden lives of ordinary things.

Desert nomads tested their vision by distinguishing a pair of stars. But we have since created more disquieting ways to test the strength of the eyes.

Reading the eye chart is an exercise in failure, since it only gets interesting when you cannot read any further. It is the opposite of interpretative reading, like one does with literature. When you have finished reading an eye chart, what exactly have you even read? From a Spanish cleric's Renaissance guide to testing...