| to correct astigmatism | 4 | purpose |
| often | 3 | degree |
| implant → be → specific | 6 |
| implant → be chosen by → patient | 4 |
| implant → be → patient-specific | 4 |
| negative | neutral | positive |
| 0.134 | 0.716 | 0.150 |
| Raw frequency | 14 |
| Normalized frequency | 0.210 |
| Modifier score | 0.600 |
| Perplexity | 482.103 |