Customize the look of your Holbrook eyewear and get the best optical performance for where you use it most. All replacement lenses feature the unbeatable clarity, impact resistance and 100% UV filtering of Oakley's High Definition Optics (HDO ). High Definition Optics (HDO ) is a collection of patented technologies that allow Oakley eyewear to meet or exceed the testing standards of the American National Standards Institute for optical clarity, visual fidelity, and impact resistance.