In addition, how you apply SPF is important, too, and it seems we aren't slathering on the moisturizer as thoroughly as a regular SPF. In fact, the study concluded that people missed 16% of their face on average, compared to sunscreen at 11%. Matthew Gass, of the British Association of Dermatologists, said: "A good way to prevent this from becoming an issue is to wear sunglasses and reapply sunscreen regularly. This should help protect the bits you miss from being exposed to excessive sun."