When anxious teenagers finally go to get that sovereign rite of passage into adulthood called the “driver’s license,” they have to pass a tricky written test and a nerve-racking driving test. But there is a third test they must pass as well: A vision test.

It is one of the odder quirks of the DMV (Division of Motor Vehicles) that the eye exam is often given last — suggesting that knowing the rules and operating a vehicle are more important than being sure you can see where you are going!

For most drivers, the eye exam is nothing, takes virtually no time, and hardly registers as a “test.” That is, until you reach a certain age. For older drivers the one exam they cannot study for, the one skill they cannot improve with practice, the one exam over which they have the least control, becomes…