人眼波前像差测量与矫正的研究

发布时间：2019-03-08 15:12

【摘要】：眼睛是心灵的窗户，它的健康与否直接关系到每个个人的生活质量。然而，同所有的实际光学系统一样，人眼不是一个完善的屈光系统，存在着各种像差，其中不仅含有离焦、散光在内的各种低阶像差，还包括诸如三叶草，四叶草等在内的高阶像差。长期以来，人们对人眼像差的测量和矫正主要集中在离焦、散光等低阶像差项上，这一方面是因为统计意义上来讲，这类像差对于人类的视力影响最大；另一方面，也是由于人类的镜片磨制技术只能矫正离焦、散光之类的低阶像差。随着准分子激光手术的发展和普及，屈光手术已经得到了广泛的应用，但患者术后的并发症也困扰着医生和病患。其中部分原因是由于对于高阶像差测量的不完备导致角膜手术后患者眼的像差失控，深入理解和准确测量人眼高阶像差对于有效控制角膜手术效果，提高病患生活质量无疑有着重要意义。本文沿着上一届师兄的主客观结合的人眼像差测量平台思路出发，详细讨论了这一人眼像差光学测量系统搭建过程中可能存在的误差，并对其进行了仔细地定量分析和计算。根据计算结果，，我们提出了基于客观测量数据的光学系统安装与调节方案。在此基础之上，提出了优化了的主客观相结合的人眼像差测量光路，分析并给出了眼瞳与HSS测量孔径不匹配情况下的像差还原代数方法。本文将以如下线索展开：从波前像差的基本概念出发，介绍波前像差的基本理论，并详细地分析了Zernike多项式各阶项对应表达式的含义；对Hartmann-Shack传感器测量人眼像差的原理进行了详细分析，给出了Hartmann-Shack传感器可测量范围的公式和波前重构的基本公式，计算了传感器的测量局限；分析了参考面上波前形状对最终测量得到的被测波前结果的影响，计算并给出了基于客观的准直照明光束调节方法，从而使得我们以较高的精度和可重复地获得了接近理想的参考波前；提出了应用HSS参与调节整个人眼测量光路的系统方法，解决了由于光学镜片制造公差、设计波长与实际波长的不同所造成的包括离焦像差在内的各种透镜误差所可能带来的系统安装误差，使得我们能够对的光学测量平台的搭建精度予以准确地判断，并使得我们的测量结果具备信服，可靠，可重复的特点；引入了调节同轴度更高的照明光束预调节系统，提高信噪比的同时解决了同轴度调节困难的问题；引入了用于减小激光散斑影响的消散斑光路，对其消除散斑的可行性进行了实验研究；提出了允许主观参与调节的主客观相结合的人眼像差测量系统；在实验部分，我们分别用实验的方法研究了人眼主观调节对像差的改善、佩戴镜框眼镜对低阶和高阶像差的改善以及应用可变形镜实时矫正人眼像差的可能性。进行较为全面的实验分析与研究工作。
[Abstract]:The eye is the window of the soul, and its health is directly related to the quality of life of each individual. However, like all practical optical systems, the human eye is not a perfect refractive system, and there are aberrations, not only of low order aberrations, including defocusing, astigmatism, but also of clover, High-order aberrations, such as clover, etc. For a long time, people mainly focus on low-order aberrations such as defocus, astigmatism and so on. On the one hand, these aberrations have the greatest influence on human visual acuity in the statistical sense. On the other hand, it is also because human lens grinding techniques can only correct low-order aberrations such as defocus and astigmatism. With the development and popularization of excimer laser surgery, refractive surgery has been widely used. Part of the reason is that the incomplete measurement of high-order aberrations leads to out-of-control of the aberrations in the eyes of the patients after corneal surgery, and in-depth understanding and accurate measurement of the high-order aberrations of the human eye are effective in controlling the effect of corneal surgery. There is no doubt that it is of great significance to improve the quality of life of the patients. In this paper, the possible errors in the construction of the optical measurement system of human eye aberration are discussed in detail according to the train of thought of the previous brother's subjective and objective human eye aberration measurement platform, and its quantitative analysis and calculation are carried out in detail. According to the calculation results, we propose an optical system installation and adjustment scheme based on objective measurement data. On the basis of this, the optimized optical path of human eye aberration measurement combined with subjective and objective is proposed, and an algebraic method of aberration reduction under the condition that the pupil does not match the aperture of HSS measurement is analyzed and given. Based on the basic concept of wavefront aberration, this paper introduces the basic theory of wavefront aberration and analyzes in detail the meaning of the corresponding expressions of every order term of Zernike polynomials. The principle of measuring human eye aberration by Hartmann-Shack sensor is analyzed in detail. The formula of measurable range of Hartmann-Shack sensor and the basic formula of wavefront reconstruction are given, and the measurement limitation of the sensor is calculated. The influence of the wavefront shape on the reference surface on the measured wavefront results is analyzed, and the objective collimating illumination beam adjustment method is given. Thus we can obtain reference wavefront with high precision and repeatability. In this paper, a systematic method of adjusting the optical path of the whole human eye by using HSS is presented, and the tolerance of optical lens manufacturing is solved. The system installation error caused by different design wavelength and actual wavelength caused by various lens errors, including defocusing aberration, enables us to accurately judge the accuracy of the optical measurement platform. And make our measurement result have convincing, reliable, repeatable characteristic; The pre-adjusting system of illumination beam with higher coaxiality is introduced to improve the signal-to-noise ratio and solve the difficult problem of coaxiality adjustment at the same time. An experimental study on the feasibility of eliminating speckle is carried out by introducing the speckle light path which is used to reduce the influence of laser speckle, and a human eye aberration measurement system which allows subjective participation and objective adjustment is proposed. In the experimental part, we used experimental methods to study the improvement of subjective adjustment aberration, the improvement of low and high order aberrations with glasses, and the possibility of real-time correction of human eye aberrations with deformable lenses. Carry out more comprehensive experimental analysis and research work.
【学位授予单位】：上海理工大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：O43;R77

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