No one can put it better than Oakley themselves...
"We gave the Oakley Split Jacket® interchangeable lenses with Switchlock™ technology that makes lens changing easy and fast. Accented with true metal icons, the lightweight frame is made of stress-resistant O Matter® with Unobtainium® stem sleeves and nose pads that actually increase grip when you sweat. Our Three-Point Fit optimizes comfort while keeping the lenses in precise optical alignment. Take a close look at how the lenses contour at the sides, maximizing protection against sun, wind and side impact. It's a full 8.75 base lens curvature that utilizes patented XYZ Optics® to offer razor sharp clarity at every angle of view. You'll have extended peripheral vision and performance that meets ANSI Z87.1 standards, thanks to High Definition Optics® (HDO®). Oakley HDO® also means protection, so Split Jacket meets ANSI Z87.1 standards for high velocity and high mass impact resistance.
Our Plutonite® lens material filters out every eye-baking ray of UV, not just UVA and UVB, and you'll have a wide array of lens options to adapt to any environment. When reflected glare threatens your vision, install optional Oakley HDPolarized lenses. They're made without the haze and visual distortion of ordinary polarized lenses, and they filter out greater than 99% of glare while offering the performance of HDO®. No wonder they're considered the best polarized lenses on the planet. Other options include lenses with Iridium® coating to balance light transmission and further reduce glare, as well as Transitions® SOLFX™ lenses that adapt to changing light with photochromic technology. You can also get Oakley Authentic Prescription Lenses with +2.00 to -3.00 combined power, and numerous options are available for our corrective optics."
Split Jacket comes with an Oakley Soft Vault case that stows the lens/frame combination and an extra pair of optional lenses