I am looking to buy my boyfriend 509 goggles for christmas. Problem is, i have no idea what i am looking at. He told me he wants a pair but not what type. Stealth Polarized, Storm Polarized? If i choose one of the polarized aviator colors does that mean choosing polarized lenses would be pointless? Or does that come separate? What are the best spare lenses? Is the Anti-Fog Goggle Fan Module worth it? I have no idea about any of this stuff please help!