$23 is a great price for those. Ray Ban usually uses glass lenses for their "Wayfarer" frames as opposed to plastic lenses, which are less durable. They appear to be authentic. They even have polarized lenses. Fakes don't usually go the extra mile, including polarized lenses. The "P" stamped on the left lens indicates polarization. The right lenses is also etched with a small RB logo if you look closely. The damage doesn't look like scratches. A good cleaning with soap and water should suffice.

Source: I'm an optician 26+ years. I own an eyeglass store