This is my fourth frame with Tajima prescription sunglass lenses. I had been extremely happy with my three other frames with Tajima lenses but wanted something more specific for my beach sports activities (mainly beach tennis). I had a pair of Kaenon X-Kores and reached out to Jacob to see what could be done. He suggested a process called Digital Edge Thinning to make the lenses work better for the curvature needed for the X-Kore frame. The extra charge was minimal and I'm happy to say the results were nothing short of Tajima's standards that I experienced with my other three frames!