Vogels R, Orban G A, Vandenbussche E
Invest Ophthalmol Vis Sci. 1984 Jun;25(6):720-8.
Orientation discrimination for single long lines presented in a frameless environment was measured with a method of constant stimuli in 18 normal subjects and in both eyes of 9 amblyopes. Orientation discrimination was tested at four meridians (horizontal, vertical, left, and right oblique). Although the normal subjects showed considerable individual variability in their just noticeable differences in orientation, each subject showed a consistent oblique effect. In amblyopic subjects, the interocular differences were strongly meridian-dependent and individually variable. Across amblyopic subjects, a two-fold increase in just noticeable differences ( JNDs ) was observed for the principal meridians, while the impairments were not significant for the oblique meridians. These small impairments in orientation discrimination strongly contrast with the high losses in acuity for the same subjects, which suggests that different mechanisms underly acuity and orientation discrimination.
在无框架环境中呈现单条长线时，采用恒定刺激法对18名正常受试者以及9名弱视患者双眼的方向辨别能力进行了测量。在四个子午线（水平、垂直、左斜和右斜）上测试了方向辨别能力。尽管正常受试者在方向辨别上的最小可觉差表现出相当大的个体差异，但每个受试者都表现出一致的倾斜效应。在弱视受试者中，两眼间差异强烈依赖子午线且个体差异较大。在所有弱视受试者中，主要子午线的最小可觉差增加了两倍，而倾斜子午线的损伤不显著。方向辨别上的这些微小损伤与同一受试者的视力高度损失形成强烈对比，这表明敏锐度和方向辨别是由不同机制引起的。
