| Description | They employ Lea Symbols®. Contrast levels are the same at 25%, 10%, 5%, 2.5% and 1.25%. Each offers a different set of Lea Symbols® to guard against memorization. Also uses recording forms (P/N 215400). Legend card provided. | These Low Contrast Flip charts contain 5 pages of various contrast levels showing 5 Lea Numbers® on each page. Optotype size is 9.5M. Contrast levels are 25%, 10%, 5%, 2.5% and 1.25%. These flip charts can be used at several different distances. |