Bastian G O, Kegel J
Fortschr Ophthalmol. 1989;86(4):387-91.
Psychophysical determination of the thresholds of stereoscopic vision takes about 20 min. During this procedure, you may have the feeling that the thresholds are shifting. To verify this phenomenon, the thresholds must be determined in a period shorter than 20 min, e.g., 4-6 min. This is one of the reasons we constructed a computerized machine to detect the stereoscopic thresholds. The heart of this device is a micrometric screw driven by a stepping motor that moves the central rod of the three-rod apparatus. This motor is controlled by a microcomputer with a basic program. A special program has been designed that functions in a manner similar to that of the Octopus perimeter and detects the thresholds with in a few steps. It is thus possible to reduce the detection time for one threshold dramatically. The first results with this device are not only very precise, but also demonstrate the minute values between stereoscopic thresholds. For an observation distance of 380 mm, we were able to calculate the disparation angles down to 3 s of arc. If a number of measurements are taken, the threshold fluctuations and physiological zero position can be calculated.
立体视觉阈值的心理物理学测定大约需要20分钟。在此过程中，你可能会感觉阈值在变化。为了验证这一现象，必须在短于20分钟的时间段内，例如4 - 6分钟内测定阈值。这就是我们构建一台计算机化机器来检测立体阈值的原因之一。该设备的核心是一个由步进电机驱动的测微螺杆，它移动三杆装置的中心杆。这个电机由一台带有基本程序的微型计算机控制。已经设计了一个特殊程序，其功能类似于章鱼视野计，能在几步之内检测出阈值。因此可以大幅减少检测一个阈值的时间。使用该设备得到的首批结果不仅非常精确，还展示了立体阈值之间的微小数值。对于380毫米的观察距离，我们能够计算出低至3角秒的视差角。如果进行多次测量，就可以计算出阈值波动和生理零位。
