Constants used for the different formulas
| Formula | Lens constant | Optimised constant |
| Barrett Universal | Lens factor | 118.75 |
| Haigis | a0, a1, a2 | −0.946, 0.234, 0.217 |
| Hill 2.0 | A constant | 118.69 |
| Hoffer Q | ACD | 5.457 |
| Holladay 1 | Surgeon factor | 1.68 |
| Holladay 2 | ACD | 5.345 |
| Kane | A constant | 118.73 |
| Olsen | ACD | 4.47 |
| SRK/T | A constant | 119.05 |