For some of us, the Oakley Bottlecap, or the groundbreaking (for its dual lens interchangeability) Half Jacket was our very first pair of sports sunglasses. That was over ten years ago, and both styles can still be readily found in the retail sector - this speaks a great deal to the universal fit and radical design. In regard to the Half Jacket, it excelled in fit and durability, but lacked somewhat in timelessness. This is why Oakley has seen fit to update the design with the Half Jacket 2. 0 XL Polarized, while still presenting the same core fit and interchangeable lens functionality that made the original such a classic. From a design standpoint, most immediately apparent is how the 2. 0 mixes the outwardly curved and slightly wider fit profile of the Half Jacket, with the more confident hinges and sculpted earstems of the recent Fast Jacket. The Half Jacket 2. 0 XL is available with a Oakley's excellent lens polarization. What makes Oakley polarizing different is that they figured out how to integrate the filter into their lenses without applying glue. Their competitors typically sandwich the filter between thin layers of lenses using clear glue. The glue is often the source of the slight distortion you experience when wearing some polarized glasses. Another plus of Oakley polarizing is they make both the right and left lenses at the same time and cut them out in parallel pieces so the filter lines up exactly the same way for both eyes. This is one less piece of optical information for your eyes and brain to adjust to: another reduction in eyestrain. Like every Oakley design that leaves their Foothill Ranch factory, the Half Jacket 2. 0 XL not only meets, but exceeds the rigorous standards set by the American National Standards Institute (ANSI). Granted, the worst that most of us will ever see is the occasional tree branch, or fast-flying insect, but Oakley still designs their lenses to withstand impacts as great as these, keeping your eyes protected whereve.