Designed for those with a smaller face shape, SI Tombstone Spoil lens is their most advanced shooting eyeshield delivering unprecedented performance for the modern day marksman. They focused on three specific areas: Field of View, Contrast/Clarity, and Lens Interchangeability. Using eye-tracking technology, they identified the key zones in your field of view to allow for 120 degrees of vision. Oakley incorporated PRIZM? technology to provide contrast enhanced viewing to help lock in your target and decrease eye fatigue/eye strain.