Loshin D S, Levi D M
Doc Ophthalmol. 1983 May 1;55(3):213-36. doi: 10.1007/BF00140810.
Three experiments were conducted to investigate suprathreshold contrast perception of a group of strabismic and anisometropic amblyopes. In the first experiment, simple reaction-time was measured as a function of the contrast of sinusoidal gratings. At all contrast levels, the amblyopic eyes showed prolonged reaction-times compared to the non-amblyopic eyes. In the second experiment, the perceived contrast of suprathreshold sinusoidal gratings was measured using an interocular successive matching paradigm. The third experiment compared perceived contrast of the amblyopic and non-amblyopic eye by contrast magnitude estimation. The results of the matching and magnitude estimation experiments showed that while amblyopic observers show large losses of contrast sensitivity at threshold, at suprathreshold contrast levels perceived contrast is essentially normal or near normal in the amblyopic eye. Taken together, these experiments suggest that: 1) the amblyopic eye has a higher contrast gain than the non-amblyopic eye, and 2) the amblyopic eye shows prolonged response latencies. Similar results can be obtained in normal observers under conditions of peripheral viewing and noise masking.
进行了三项实验来研究一组斜视性和屈光参差性弱视患者的阈上对比度感知。在第一个实验中，测量了简单反应时间作为正弦光栅对比度的函数。在所有对比度水平下，弱视眼与非弱视眼相比反应时间延长。在第二个实验中，使用双眼相继匹配范式测量阈上正弦光栅的感知对比度。第三个实验通过对比度量级估计比较了弱视眼和非弱视眼的感知对比度。匹配和量级估计实验的结果表明，虽然弱视观察者在阈值时对比度敏感度大幅下降，但在阈上对比度水平时，弱视眼的感知对比度基本正常或接近正常。综合来看，这些实验表明：1）弱视眼比非弱视眼具有更高的对比度增益，2）弱视眼表现出延长的反应潜伏期。在正常观察者的周边视觉和噪声掩蔽条件下也能获得类似结果。
