25% Contrast
Notations for testing at 2.5 meters (8.5 ft.)
Acuity range 25.2M to 1M (20/200, 6/60 to 20/8, 6/2.4 equiv.)
Two groups for repetitive testing
Includes a soft-tipped pointer, recording forms (CAT. NO. 2514) and test instructions
Measures 62 X 65 cm (24.5 X 25.5 in.)
• NOTE: CAT. NO. 2425 ETDRS Illuminator Cabinet is necessary with this chart.
PV Numbers are similar to Patti Pics optotypes in the fact that both are closely calibrated to Sloan standards. These standards include proper placement on a 5x5 grid, and adequate area per optotype. Also, each number is chosen to be equally difficult compared to the other numbers. Furthermore, this equal difficulty helps PV Numbers achieve an equal blur at threshold. These standards make PV Numbers tests more accurate and reliable.
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