Protecting the face is rational, for many people it gets the most sun exposure of any part of your body. Heard from my dermatologist two of the most common skin cancer locations in our community are the lower lip and lower eyelid, which of course are two facets of your face that are most perpendicular to the sun at peak UV hours.

I figure, and this is just me, that if you want to get sun exposure, it's probably best to expose more skin for less time. If the risk is LNT, it's all the same. If it's not, you lower the total risk.