Please take a moment to watch this video about Prizm. It is truly an amazing lens design resulting from investment and research by one of the world's leading sports eye-wear companies, Oakley. I have been selling Oakley products for nearly twenty years and believe this is the most exciting design to date and is available in a range of prescriptions, both single vision and varifocal. I was amazed by the clarity, detail and contrast that I found when wearing the Oakley road lens compared to many I have tried in the past. The magic is in the technology to narrow the areas of the spectrum that the lens filters out (or leaves in!) unlike many sun specs that just dim the whole world down. Different activities from cycling to golf, water sports to climbing subject us to very varied light conditions which can often change and many of us buy sunspecs crossing our fingers that they will improve our vision and protect our eyes. Here we have product which is targeted at particular areas of lifestyle which certainly helps me to dispense lenses with more confidence and help you to enjoy the things in life that you love. They even do a general daytime version, so there's something for everyone!