LEA Symbols Low Contrast Flip Chart | 251100
$114.00
The contrast levels of the test lines on five pages are: 25%, 10%, 5%, 2.5% and 1.2%. The LEA Symbols are the 9.5M size at 1 meter corresponds to visual acuity 20/200 (6/60, 0.1), at 2 meters to 20/100 (6/30. 0.2) at 4 meters 20/50 (6/15, 0.3.