BONUS: To see adequately for night driving, a typical 60-year-old needs about _____ the light he needed at age 21.
B. four times
C. eight times
The answer is C. The amount of light you need to drive—or even see—at night doubles every 13 years. As you age, the retinas in your eyes become less able to absorb light. At the same time, the pupils of your eyes become smaller and the lenses can yellow, letting less light in. If you’re having trouble seeing the taillights of the cars ahead or spotting road signs at night, it might be time for you to limit your night driving.