Reading time for each of the five chart designs
| Chart | Minimum | 25th centile | Median | 75th centile | Maximum |
| ETDRS | 41 | 79 | 106 | 147 | 405 |
| RLM A | 13 | 42 | 59 | 75 | 182 |
| RLM B | 14 | 22 | 34 | 54 | 161 |
| RLM C | 19 | 34 | 47 | 70 | 104 |
| Snellen | 19 | 70 | 110 | 161 | 417 |
Figures are time taken in seconds to complete a chart reading—that is, measurement
time excluding score calculation time.