Description
The charts come as a set of two panels (21x24inches, 53x60cm) each with a high contrast chart one side and a low contrast chart (18% Weber or 10% Michelson) on the other. The optotype set is the family of ten British Standard (1968) 5x4 non-serifed letters. There are 14 rows with a range of sizes from 38 to 1.9 M-units. Sizes are given in Snellen units (in both feet and metric units), as well as visual acuity values in LogMAR and VAR (Visual Acuity Rating) for a 6 meter viewing distance. Any other viewing distance may be used as well. A scale printed on each chart provides the score adjustment for different test distances. With the LogMAR and VAR scales, equal credit is given for each additional letter read (each extra letter earns -0.02 with LogMAR , or 1 point with VAR)