Statistical variation of aberration structure and image quality in a normal population of healthy eyes
Statistical variation of aberration structure and image quality in a normal population of healthy eyes
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DOI：
10.1364/josaa.19.002329
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发表时间：
2002-12-01
影响因子：
1.9
通讯作者：
Cheng, X
中科院分区：
文献类型：
--
作者：
Thibos, LN;Hong, X;Cheng, X
用Shack-Hartmann像差仪测量了100人200只正常健康的睫状肌麻痹眼的主视线方向的单色像差结构沿着。根据实验前即刻进行的主观验光结果，用眼科眼镜片矫正球柱镜屈光不正。Zernike展开的实验波前像差函数被用来确定一系列的瞳孔直径的像差系数。散焦的残余Zernike系数不为零，而是以最大化视觉敏锐度的方式随着瞳孔直径和球面像差的Zernike系数系统地变化。我们从这些结果中推断，主观最佳聚焦发生在瞳孔的中心无像差区域的面积最大化时。我们发现除了球差外，所有高阶模的Zernike系数的总体平均值几乎为零。这一结果表明，一个假设的平均眼睛代表人口的集中趋势几乎是免费的畸变，这表明可能的影响正视化过程或进化压力。然而，对于任何单个眼睛的像差系数很少为零的任何泽尼克模式。在一阶近似下，波前误差随Zernike阶数呈指数下降，随瞳孔面积呈线性增加。平均而言，高阶像差产生的总波前方差小于残余散光和散光的波前方差。例如，对于7.5mm瞳孔存在的高阶像差的平均量等于由小于1/4屈光度（D）的散焦产生的波前误差。最大的瞳孔，眼睛可以被认为是衍射限制的平均为1.22毫米。左右眼像差的相关性表明存在显著的双侧对称性。没有证据表明，一个普遍的解剖特征负责三阶光学像差。使用.根据Marechal准则，我们得出结论，对于6 mm的光瞳，平均而言，将需要校正12个最大的主分量或14个最大的Zernike模式以实现衍射极限性能。不同的方法计算人口平均值提供了上限和下限的平均光学传递函数和平均点扩散函数为我们的人口的眼睛。(C)2002年美国光学学会。
A Shack-Hartmann aberrometer was used to measure the monochromatic aberration structure along the primary line of sight of 200 cyclopleged, normal, healthy eyes from 100 individuals. Sphero-cylindrical refractive errors were corrected with ophthalmic spectacle lenses based on the results of a subjective refraction performed immediately prior to experimentation. Zernike expansions of the experimental wave-front aberration functions were used to determine aberration coefficients for a series of pupil diameters. The residual Zernike coefficients for defocus were not zero but varied systematically with pupil diameter and with the Zernike coefficient for spherical aberration in a way that maximizes visual acuity. We infer from these results that subjective best focus occurs when the area of the central, aberration-free region of the pupil is maximized. We found that the population averages of Zernike coefficients were nearly zero for all of the higher-order modes except spherical aberration. This result indicates that a hypothetical average eye representing the central tendency of the population is nearly free of aberrations, suggesting the possible influence of an emmetropization process or evolutionary pressure. However, for any individual eye the aberration coefficients were rarely zero for any Zernike mode. To first approximation, wave-front error fell exponentially with Zernike order and increased linearly with pupil area. On average, the total wave-front variance produced by higher-order aberrations was less than the wave-front variance of residual defoeus and astigmatism. For example, the average amount of higher-order aberrations present for a 7.5-mm pupil was equivalent to the wave-front error produced by less than 1/4 diopter (D) of defocus. The largest pupil for which an eye may be considered diffraction-limited was 1.22 mm on average. Correlation of aberrations from the left and right eyes indicated the presence of significant bilateral symmetry. No evidence was found of a universal anatomical feature responsible for third-order optical aberrations. Using. the Marechal criterion, we conclude that correction of the 12 largest principal components, or 14 largest Zernike modes, would be required to achieve diffraction-limited performance on average for a 6-mm pupil. Different methods of computing population averages provided upper and lower limits to the mean optical transfer function and mean point-spread function for our population of eyes. (C) 2002 Optical Society of America.