Table 5. Visual acuity values for each phosphene pattern.
| Phosphene Pattern | Central Phosphenes (count) | FSD Acuity (LogMAR, Snellen) | i75 Acuity (LogMAR±95% confidence, Snellen) | ||
| P1 | 370 | 1.00 | 20/200 | 1.08±0.09 | 20/240 |
| P2 | 110 | 1.30 | 20/400 | 1.37±0.08 | 20/470 |
| P3 | 45 | 1.30 | 20/400 | 1.68±0.09 | 20/960 |
| P4 | 25 | 1.60 | 20/800 | 2.00±0.13 | 20/2000 |
For each phosphene pattern under test, Pi, the number of phosphenes in the central part of vision is shown, followed by the population mean acuity using the two criteria of first significant deviation from chance, and interpolated 75% hit rate (see main text). The FSD acuity corresponds to the stimuli where the population response first differs significantly from chance (p<0.001 for all except P3 for which p<0.02), whereas the i75 acuity corresponds to the 75% performance level of a sigmoid fitted to the population data. Uncertainties shown for i75 values represent 95% confidence ranges.