A beach lover's dream: A step toward long-lasting sunscreen

In a perfect world, people would diligently reapply suncreen every couple of hours to protect their skin from damaging solar radiation. But few people actually adhere to reapplication guidelines, and those who do hardly relish the task. To develop longer-lasting sunscreens, researchers are trying to answer a basic question: How do sunblock ingredients work?

(via WSJ)