Spiro Cardboard Sensor

Test for quick measurement of low Contrast visual acuity at 25%, 10%, 5%, 2.5%, and 1.25% Contrast by measuring the distance where the symbols are seen. 10M symbols correspond to visual acuity 0.10 at 1 m, 0.05 at 0.5 m and 0.3 at 3 m. VA values are thus easy to calculate. Test includes a table for conversion to Snellen equivalent VA values, a response keys and instructions. 6 pages, 3.25″ x 9″ (8.25 cm x 22.9 cm).