I learned something recently that I hadn't really considered before. When we use a face moisturiser or foundation with spf, we may well not be protected in the way we think.
We need protection from both UVA and UVB, as they both cause different problems to our skin. UVA tends to be responsible for wrinkles and photo-ageing (sun spots etc) while UVB is largely responsible for sun burn. They both contribute to skin cancers.
Its common that our added spf only cover one of these, not both, although they do exist. Definitely worth a check though, as no one enjoys the damaging effects of the sun. I'm off to investigate my makeup bag and see if I need to make any replacements. I'd been smugly proud of my use of a moisturiser with spf along with my primer with an spf, but now I'm not so sure!