A very good friend of mine is a skin dr. And let me tell you he has told us stories that would make you slather on sunscreen every waking moment! Even the skin that is not exposed is effected. He said you can even get it between your toes and under your hair.He says he does a thorough head check on all he's clients.
Even if you don't think you burn wear sunblock. The results of not are far worse then your eye's stinging