Schor C, Bridgeman B, Tyler C W
Invest Ophthalmol Vis Sci. 1983 Dec;24(12):1572-9.
The spatial and temporal organization of stereoscopic depth perception were compared in normal and strabismic observers. The minimum and maximum disparities for stimulating static and dynamic stereopsis in strabismus were examined as a function of spatial separation of disparate stimuli. Disparities and their spacing were produced by spatial modulation of two vertical lines viewed haploscopically. Most strabismics had normal upper disparity limits but elevated static and dynamic stereothresholds. Moderate stereothreshold elevations (100 arc sec) were constant for spatial separations greater than 15 arc min. Two new types of spatial crowding effects upon stereopsis were observed. The first type resulted from the constant elevation of the disparity threshold. The second type consisted of a reduced maximum disparity limit for stereopsis. In both cases, the constriction of the range of perceivable depth produced a reduction in the spatial and temporal frequency limits for depth perception. Clinical tests of stereoacuity that crowd stimuli closer than 0.25 degree underestimated the strabismic patients' potential stereoacuities by a factor of 2 to 4. Similarly, tests of dynamic stereopsis that use temporal frequencies greater than 1 Hz will underestimate optimal dynamic stereoacuity.
对正常观察者和斜视观察者的立体深度感知的空间和时间组织进行了比较。研究了斜视中刺激静态和动态立体视觉的最小和最大视差，作为不同刺激空间分离的函数。视差及其间距通过单眼观察的两条垂直线的空间调制产生。大多数斜视患者的上视差极限正常，但静态和动态立体视觉阈值升高。对于大于15角分的空间分离，中等程度的立体视觉阈值升高（100角秒）是恒定的。观察到两种新型的空间拥挤对立体视觉的影响。第一种类型是由于视差阈值的持续升高。第二种类型包括立体视觉的最大视差极限降低。在这两种情况下，可感知深度范围的缩小导致深度感知的空间和时间频率极限降低。将刺激物聚集在小于0.25度的临床立体视敏度测试将斜视患者的潜在立体视敏度低估了2至4倍。同样，使用大于1Hz的时间频率的动态立体视觉测试将低估最佳动态立体视敏度。
