Damgaard IB, et al. - Investigators analyzed the centration and functional optical zone (FOZ) after small incision lenticule extraction (SMILE) vs femtosecond laser–assisted in situ keratomileusis (LASIK) in this prospective, randomized, single-masked, paired-eyed, clinical trial with 70 subjects receiving SMILE in one eye and LASIK in the other eye for myopia and myopic astigmatism. They noted comparable values of the average preoperative spherical equivalent (−5.38 ± 1.65 vs −5.45 ± 1.61 diopters [D]), postoperative spherical equivalent (0.05 ± 0.39 vs 0.06 ± 0.39 D), uncorrected distance visual acuity (0.01 ± 0.13 vs 0.00 ± 0.08 logMAR), and corrected distance visual acuity (−0.07 ± 0.10 vs −0.07 ± 0.10 logMAR) in SMILE- vs LASIK-treated eyes of the 60 candidates with complete datasets. Despite the smaller programmed OZ diameter (6.48 ± 0.08 vs 6.52 ± 0.11 mm) and smaller programmed treatment area (33.87 ± 0.81 vs 46.30 ± 2.61 mm²), they found that postoperative increase in spherical aberration was lower in SMILE in comparison with LASIK (0.08 ± 0.16 vs 0.17 ± 0.18 µm). Significantly larger FOZ area was recorded in SMILE as compared to in LASIK (30.25 ± 3.60 vs 29.21 ± 3.72 mm²).