Lea Symbols Test Cards, by Goodlite, are designed to measure visual acuity with a line test. Proportionally-spaced (LogMAR) with two line tests with tighter spacing (50% and 25%). The test with 25% spacing often reveals difficulties in seeing tightly spaced details, which should be known when a child starts learning to read. Line sizes range from 20/400 to 20/10 (6/120 to 6/3) equivalent, 0.05 to 2.00. Response key printed on test card. Includes training cards and instructions. Card measures 8" x 10" (20.3 cm x 25.4 cm). 16 inches/40 centimeters testing distance.