landolt
美
英 
例句
Landolt 5: 1 C letters could not completely get rid of the interference of diffraction and crowding phenomenon.
蓝氏5:1视标无法完全避开局部绕射的干扰及拥挤现象的影响。
Visual acuity test types - Specification for Landolt ring optotype for non-clinical purposes
视觉敏锐度测验.非临床用缺口环验光字体规范