easily measure, record, and detect changes in the transfer of visual information when the change affects only visual acuity at low contrast levels - charts include the following contrast levels: 25%, 10%, 5%, 2.5%, and 1.25% - pages are offset for easy flipping - each chart includes recording forms and instructions - 5 pages, 3.25" x 9" (8.25 cm x 22.9 cm)