Aside from the obvious, polarized non polarized, the OO is a G40 base and Positive is Gray. OO also has more transmission at 18% vs. 25% and I understand you can see eyes through OO Red pretty easily. To my eye Positive contains more purple/blue to it, which I like. Not real thrilled with OO Red personally...another new lens with oddly high and insanely impractical light transmission characteristics