This "revised" eye chart incorporates a slight change in the difficulty score for each of the ten SLOAN letters derived from the best corrected visual acuity examinations of 7,420 eyes during the ETDRS study.
For vision testing at 2 meters (6.5 ft.)
Acuity range 20M to 1M (20/200, 6/60 to 20/10, 6/3 equiv.)
Measures 62 X 65 cm (24.5 X 25.5 in.)
Fits ETDRS Illuminator Cabinet CAT. NO. 2425
Can also be wall mounted
ETDRS "2000" Series charts feature listed equivalents on each side of the chart. These include LogMar, Decimal, Feet, and Meters.
"2000" Series ETDRS charts differ from "Original" Series charts only slightly. "2000" Series chart use different difficulty scores for each of the 10 Sloan optotypes used in the chart. Also, the configuration of these optotypes differ in use due to the fact that they are featured in each position on the chart at least once. This configuration helps to create equality in difficulty throughout each line. An equally difficult ETDRS chart means that it is more reliable and more accurate.
IS
