BS 4274-1:1968

Visual acuity test types-Specification for test charts for clinically determining distance visual acuity

BSI Group , 01/26/1968

$80.00 $160.02

Basic requirements for test charts designed for either internal or external illumination, employing English (Roman) capital letters to determine the distance visual acuity. Provision is also made for the single letter C (Landolt or broken ring) and the single letter E (illiterate E) in various orientations.