Absolute spherical equivalent refractive errors for the five different formulae. Similar data shown for control eyes using the SRK-T formula
| Mean AE, in D (95% CI) | AE range (D) | AE within 0.5D (%) | AE within 1D (%) | AE within 2D (%) | |
| CHM | 1.15 (0.52 to 1.78) | 0.08–5.30 | 31.6 | 68.4 | 79.0 |
| Masket | 0.78 (0.43 to 1.13) | 0.02–2.83 | 42.1 | 73.7 | 94.7 |
| Haigis-L | 0.84 (0.52 to 1.16) | 0.00–2.93 | 40.9 | 68.2 | 90.9 |
| Shammas-PL | 0.71 (0.46 to 0.96) | 0.03–2.24 | 50.0 | 77.3 | 100.0 |
| Barrett True-K | 0.69 (0.43 to 0.91) | 0.13–2.43 | 40.9 | 86.4 | 95.5 |
| Control patients | 0.49 (0.32 to 0.66) | 0.06–1.25 | 55.6 | 88.9 | 100.0 |
AE, Absolute error (absolute value of the difference between the Intended and postoperative spherical equivalent refractive error); CHM, clinical history method; D, dioptres; Shammas-PL, Shammas post-Lasik.