Um... squinting? I swear, she is a native English speaker. (And a librarian, which doesn't explain why she couldn't figure out how to leave a comment herself on the blog.)
She suggested sunglasses. I ran with a pair for a few weeks one summer ages ago and didn't like it - that's when I discovered the baseball hat, which has been my warm weather go to ever since. But I don't wear one in the winter: could she be on to something?