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研究了明视觉下亮度变化对神经对比敏感度函数(NCSF)的影响。分别测量人眼的对比敏感度函数(CSF)和调制传递函数(MTF),而后通过计算的方法获得白光的NCSF。运用这种方法对4只人眼进行白光(15,210和310cd/m2)下的NCSF测定。测试结果表明:白光的NCSF均随着亮度的增加有较大幅度的提高,并且曲线向着高空间频率方向移动,提高的幅度和移动的大小存在个体上的差异。CSF的变化趋势类似于NCSF的变化趋势,但在亮度的影响下,CSF的相对增长幅度要高于NCSF的相对增长幅度,这种情形在高频部分尤为突出。由于NCSF反映的是排除了眼屈光系统的从视网膜到大脑的视觉特性,因此NCSF随亮度的变化才是视觉的神经系统对亮度敏感特性的客观反映。
The effect of brightness change on neural contrast sensitivity function (NCSF) under bright vision was studied. The contrast sensitivity function (CSF) and modulation transfer function (MTF) of the human eye were separately measured, and then the white light NCSF was obtained by calculation. Four human eyes were subjected to NCSF measurements in white light (15, 210 and 310 cd / m2) using this method. The test results show that the NCSF of white light increases greatly with the increase of brightness, and the curve moves toward the direction of high spatial frequency. There is an individual difference between the magnitude of increase and the size of the movement. The changing trend of CSF is similar to that of NCSF. However, under the influence of brightness, the relative growth of CSF is higher than that of NCSF, especially in high frequency. Because the NCSF reflects the visual characteristics of the retina from the retina to the brain, the change of the NCSF with brightness is an objective reflection of the brightness-sensitive properties of the visual nervous system.