人眼不同瞳孔直径波前像差特性分析

Property analysis of wavefront aberration of different human eye’s pupils

采用Hartmann-Shack人眼像差仪,测量了人眼在3.1mm,5.2mm和6mm瞳孔直径下的波前像差。波前像差的RMS值表明,随着瞳孔直径的增大,人眼各阶波前像差均随着增大。与瞳孔直径为3.1mm时相比,瞳孔直径为6mm和5.2mm时,Zernike2-10阶波前像差的RMS值分别增大1.2-7.7倍和1.1-4.8倍。用调制传递函数(MTF)和Strehl比评价了高阶波前像差对成像质量的影响,结果表明,大瞳孔高阶波前像差对成像质量的影响大于小瞳孔;在3.1mm,5.2mm和6mm瞳孔直径下,欲达到衍射极限的Strehl比率,分别需要矫正Zernike波前像差前2-4阶、前3-6阶和前5-7阶,需矫正的像差阶数随瞳孔直径的增大而增加。

The wavefront aberrations of human eyes at 3.1 mm, 5.2 mm and 6 mm pupil diameters are measured by Hartmann-Shack human eye aberrometry. The RMS values of wavefront aberrations shows that human eye's wavefront aberrations increase with the increase of pupil diameter, the RMS values of Zernike 2-10 orders wavefront aberrations at 6 mm and 5.2 mm pupil diameters are 1.2-7.7 and 1.1-4.8 times larger than that at 3.1 mm pupil diameter. Imaging quality affected by high-order wavefront aberrations is evaluated through modulation transfer function (MTF) and Strehl ratio. The analysis shows that high-order aberrations at large pupil have more effect on the imaging quality than that at small pupil. To achieve Strehl ratio under diffraction limit, the orders of aberration to be corrected are pre2-4 orders, pre3-6 orders and pre5-7 orders of Zernike wavefront aberrations at 3.1 mm, 4.1 mm and 5.2 mm pupil diameters, respectively. The orders of aberration to be corrected will increase with the increase of pupil diameter.