Measures of visual acuity and contrast sensitivity
| Number of studies reporting | Distance (n=20) | Intermediate (n=4) | Near (n=20) | Contrast sensitivity (n=14) |
| Unaided | 18 | 3 | 18 | 2 |
| Best corrected (for distance) | 14 | 2 | 9 | 1 |
| Best corrected (for near) | 7 | |||
| Best spectacle corrected | 3 | 3 | ||
| Presenting (with/without prescribed spectacles) | 1 | 1 | ||
| Other | Corrected but not specified how (1 study) | −1.25 D addition (1 study) | Distance vision plus 2.75 reading additions Plus −2.5 D ‘with near correction’ Distance refraction with addition unspecified | Unclear or not reported (8 studies) Plus 2.75 D when testing near contrast sensitivity (1 study) |