For vision testing at 3 meters (10 ft.)
Acuity range 30M to 1.5M (20/200, 6/60 to 20/10, 6/3 equiv.
Only standardized format accepted in studies sponsored by the National Eye Institute
Designed for use in clinical studies and low vision evaluations where accurate, repeatable visual acuity measurements are required
Lines are of equal difficulty
Geometric progression in letter size from line to line
Letter size is only variable
Measures 62 X 65 cm (24.5 X 25.5 in.)
Eye Chart fits the ETDRS Illuminator Cabinet CAT. NO. 2425
Can be wall-mounted
ETDRS acuity vision test uses equally difficult, traditional Sloan optotypes. Uniform difficulty in optotypes create a equal progression through the entire vision test (less than a percent from line to line). The patient has a consistent level of difficulty from the beginning of the vision test, to the point that visual acuity is determined.