Purchased this pair from an estate sale. My first X metal Oakleys. I'm hoping they are authentic. Paid $70. Looks like someone used them for prescription glasses as there is a set of Oakley clear lenses that are too strong for me. I would like to find a set of the ruby lenses for it. Since I'm not to familiar with the x metals and all the different variations, what do I look for when try to find lenses? Just x metal? Or xx x metal? Thank you for your input.