Reliability: item-total correlations
| Question (item) | n | Item-total r |
| Vision | ||
| Reading newspapers (1a) | 155 | 0.72 |
| Reading numbers in a telephone directory (1b) | 155 | 0.75 |
| Reading prices (1c) | 155 | 0.76 |
| Reading labels (1d) | 155 | 0.77 |
| Recognising other people (1e) | 155 | 0.66 |
| Seeing steps (1f) | 155 | 0.67 |
| Seeing cracks in the pavement (1g) | 155 | 0.74 |
| Seeing road signs (1h) | 155 | 0.75 |
| Difficulty seeing at night (2a) | 155 | 0.70 |
| Hazy or blurry vision (2b) | 155 | 0.62 |
| Difficulty adapting to bright lights (2c) | 155 | 0.64 |
| Difficulty adapting to dim lights (2d) | 155 | 0.73 |
| In general would you say your vision is . . . (3) | 155 | 0.63 |
| Rating your current vision on a scale from 0 to 100 (4) | 155 | 0.64 |
| Impact | ||
| Pain or discomfort in the treated eye (2e) | 155 | 0.47 |
| Watering of your treated eye (2f) | 155 | 0.32 |
| Stickiness or discharge from the treated eye (2g) | 155 | 0.22 |
| The appearance of your treated eye (2h) | 155 | 0.34 |
| Other people noticing your treated eye (2i) | 155 | 0.29 |
| Felt self conscious about your treated eye (5a) | 155 | 0.46 |
| Satisfied with the appearance of your treated eye (6) | 155 | 0.24 |