Original Series ETDRS Translucent Chart "R", Chart "1", and Chart "2"
The only standardized format accepted in studies sponsored by the National Eye Institute. Designed for use in clinical studies and low vision evaluations where accurate and repeatable visual acuity measurements are required. Geometric progression in letter size from line to line, each line is of equal difficulty.
Charts measure 62 x 65cm (24.5 x 25.5 in.)
All charts fit ETDRS Illuminator Cabinet Cat. No. 2425 or can be wall mounted.
All charts have acuity range of 20/200 to 20/10, (6/60 to 6/3 equiv.)
4 meters - 40m to 2m
3 meters - 30m to 1.5m
2.5 meters - 25.2m to 1.2m
2 meters - 20m to 1m