What's the difference between this one and the "anti-fog" face shield?

Which is the clear one that comes with the GP Tech? I'm looking to get a darker visor to use for the bright, hot, sunny days here in LA. Would the anti-fog functionality matter in such a situation? Also is there any sort of polarization to these, or would it be a good idea to wear oakleys or something underneath the visor? (I typically wear them when driving my car, but I'm new to motorcycles)