Two smaller groups 7.5M to 1.5M for repetitive testing (20/50, 6/15 to 20/10, 6/3 equiv.).
Can be wall-mounted.
Landolt C vision test is considered the gold standard of alternative vision tests (such as Tumbling E, Symbol tests, and Number charts). Broken Ring C charts feature only one optotype for easy and quick vision testing of illiterate and mute patients or those not familiar with the Roman Alphabet.