HOTV 50% Spaced Crowding Bars Book

HOTV Letter Book with 50% Spaced Bars Handheld vision screening book features HOTV optotypes with 50% crowding contour line bars to provide single optotype acuity with the proper crowding effect. Optotype line sizes from 20/100 to 20/16 (6/30 to 6/4.8) equivalent. Includes response panel and instructions. 17 pages. 4" x 4" (10.2 x 10.2 cm). 10 feet, 3 meter screening distance.