基于波前技术的人眼神经对比敏感度测量

搭建了基于波前像差的神经对比敏感度(NCSF)测试系统。该系统在测试人眼空间对比敏感度(CSF)的同时,利用Hartmann-Shack波前传感器测量人眼波前像差,通过计算进而得到人眼的NCSF。与通过两种设备分别测量全视觉CSF和波前像差获得NCSF相比,该方法避免了不同测试状态下像差波动的影响,简化了测试过程;和传统激光干涉方法测量NCSF相比,该方法避免了激光干涉产生的相干噪音和激光散斑等不利因素,并且通过改变不同亮度不同颜色视标,可以得到不同亮度,不同波长下的NCSF。选用绿光视标对四例正常人眼的NCSF进行了测量,结果表明:该系统可以同时获得人眼的全视觉CSF、屈光系统调制传递函数和NCSF;在同等亮度下,不同人眼的NCSF存在个体差异;对同一个体,NCSF曲线的最大值对应的空间频率比全眼空间CSF曲线的最大值对应的空间频率高一些。

Human Eye Neural Contrast Sensitivity Function Measurement with Wave-Front Technology

Equipment is established for measuring neural contrast sensitivity functions (NCSF) of human eyes. The contrast sensitivity function (CSF) of whole eye and modulation transfer function of optical system of the eye can be measured synchronously, and the NSCF can be calculated from CSF and modulation transfer function conveniently. Compared with achieving NSCF by measuring total-vision CSF and modulation transfer function respectively by two equipments, this method considers the dynamic character of human aberrations, and simplifies the measuring course. Compared with achieving NSCF by conventional laser interference, this method avoids the disadvantages of coherent noise and laser speckle, and can achieve NSCF of different luminance and different wavelengths by changing the luminance and color of visual target. NSCF of four normal eyes are measured with green visual target, and the results show that NSCF are variable in subjects, and the corresponding spatial frequency of NSCF peak value is higher than that of spatial CSF of whole eye.