The price listed for the lenses includes a full set of lenses - Right & Left.
We do not sell only a single left or right lens. We always recommend replacing both lenses at the same time.
We make our own brand of replacement lenses. This means that the material, color, and tint/lens view of our lenses can differ from the original (OEM) lenses that come with your frames. Changing just one lens can lead to distortion or other visual issues - due to even slight differences in the lenses.