人眼的高级像差对视功能的影响

准确测量和分析人眼的高级像差有助于更好地改善视觉，具有重要的实验和临床意义。测量了实际人眼的波前像差，分析了高级像差对人眼视功能的影响。像差数据由哈特曼-夏克（Hartmann-Shack）波前传感器分别对不同瞳孔的人眼进行测量而获得，视功能的评价方法采用了调制传递函数（MTF）、对比敏感度函数（CSF）、斯特雷尔（Strehl）比率。由人眼的波前像差数据和视网膜空间像调制度（AIM）曲线直接给出了视锐度值与对比敏感度值。矫正了离焦与像散后．被测者的平均视锐度值达到了1．0，对比敏感度在低频（20c／mm）处约为52，高频（80c／mm）处约为1；矫正了前4阶像差后，平均视锐度值可提高到1．2，对比敏感度在低频（20c／mm）处提高到96，高频（80c／mm）处提高到7。实际人眼各不相同，达到理想成像需矫正高级像差的阶数也不同。矫正了前九阶像差后，均可达到理想成像，斯特雷尔比率值大于0．8。

Impact of Higher-Order Wavefront Aberrations of Human Eyes on Vision Performance

Accurate measurement of higher-order wavefront aberrations helps to improve retinal image quality and has an important clinical value.Wavefront aberrations of human eyes have been measured and the impact of higher-order aberrations on vision has been evaluated in this article.Hartmann-Shack wavefront sensor is used to measure the aberrations and the eye's vision is evaluated with modulation transfer function MTF,contrast sensitivity function CSF and Strehl ratio.Visual acuity and CSF values were directly given from wavefront aberrations and the retinal aerial image modulation AIM of human eyes.After correcting defocus and astigmatism,the average visual acuity of subjects is 1.0,the CSF value is about 52 for lower frequency 20 c/mm and about 1 for higher frequency 80 c/mm. After removing the 2nd,3rd and 4th Zernike aberrations,the average acuity reached 1.2,the CSF value is about 96 for lower frequency 20 c/mm and about 7 for higher frequency 80 c/mm. Different people has its specific aberrations,so different order of aberrations must be corrected to reach the satisfactory imaging.After correcting the 2nd up to 9th Zernike aberrations,the Strehl ratios of three subjects are all in the ideal state and the average value is greater than 0.8.