A new approach to the study of ocular chromatic aberrations

We measured the ocular wavefront aberration at six different visible wavelengths (between 450 and 650 nm) in three subjects, using a spatially resolved refractometer. In this technique, the angular deviation of light rays entering the pupil at different locations is measured with respect to a target viewed through a centered pupil. Fits of the data at each wavelength to Zernike polynomials were used to estimate the change of defocus with wavelength (longitudinal chromatic aberration, LCA) and the wavelength-dependence of the ocular aberrations. Measured LCA was in good agreement with the literature. In most cases the wavefront aberration increased slightly with wavelength. The angular deviations from the reference stimulus measured using a magenta filter allowed us to estimate the achromatic axis and both optical and perceived transverse chromatic aberration (TCA), (including the effect of aberrations and Stiles-Crawford effect). The amount of TCA varied markedly across subjects, and between eyes of the same subject. Finally, we used the results from these experiments to compute the image quality of the eye in polychromatic light.     

显然验光与不同瞳孔直径下波前像差验光的比较

目的采用波前像差仪进行客观验光,比较分析显然验光与不同瞳孔直径下含有不同高阶成分的波前像差验光的关系。方法横断面研究。选取近视及近视散光患者31例（62眼）,利用基于Hartmann．Shack原理的波前传感系统进行波前像差测量。根据所测数据计算出不同瞳孔直径下仅有离焦的屈光度,包含离焦及球差的屈光度和含有离焦、球差及二级球差的屈光度．并应用Friedman检验分析临床显然验光与这些波前像差验光屈光度的关系。结果2、3、4、5、6mm直径瞳孔下的波前客观屈光度分别与临床显然验光屈光度比较,仅含有离焦时的屈光度差异最小,球镜度差异的中位数分别为－0．540、－0．473、－0．422、－0．407、－0．290D,差异具有统计学意义（Z=99．29,P〈0．01）;柱镜度差异的中位数分别为0．193、0．142、0．119、0．078、0．065D,差异具有统计学意义（Z=30．25,P〈0．01）;平均散光轴差异的中位数分别为-2．41、-2．89、-3．03、-1．94、-2．40°,差异无统计学意义（Z=4．42,P〉0．05）。含有高阶成分的屈光度与临床显然验光差异较大。结论由波前像差计算得到的屈光度与瞳孔直径和高阶像差参与的多少有关。纳入较高阶球差后等效屈光度降低,较大瞳孔直径下无高阶像差参与的波前屈光度与临床显然验光较接近。波前验光散光轴向与主觉验光较接近。