Figure 4: Photographs before and after excimer smoothing. A: Before excimer smoothing, many concentric ridges are noted on bed surface in Host 1. B: Before excimer smoothing, many concentric ridges are noted on bed surface in Host 2. C: After 29 μm excimer smoothing with balance salt solution as smoothing agent, concentric ridges decreased but still persist in Host 1. D: After 58 μm excimer smoothing with Optisol-GS as smoothing agent, ridges at central area were deceased significantly in Host 2.