A HUMAN ACCOMMODATION MODEL

人眼调节的机制是 目前，这是一个有争议的问题，归因于各种各样的 睫状肌通过悬韧带的作用， 玻璃体对tba前段的液压作用，或一些 它们的组合。 解决这一争议是一个问题 重要性，因为年龄依赖性的振幅损失 - 老花眼-只能被理解，也许逮捕， 通过对老化的理解， 机制 因此，这项研究的长期目标是 表征人类适应过程的老化 眼睛 这项拨款建议特别关注 调节和恒河猴老视的发展。 成年恒河猴的适应性和适应性丧失将被模拟 通过分析，确定了作用在透镜上所需的力 根据小调节期间透镜变形的描述; 随着年龄的增长，力的大小和/或模式的变化将 有助于确定哪些因素的老化有助于 补偿性损失。第二类建模方法-有限 元素分析-也将被用来扩大的范围， 研究，而不需要开发一个更复杂的 分析公式 基于计算机的射线追踪研究将 用于表征成人眼中的图像形成，并且将 与人类相比。 复弹性力学的表征 用动态形状模拟法研究猕猴透镜的特性 它在谐振子中的行为的建模也将是 进行，不仅提供必要的弹性常数， 适应模型，而且还直接检验假设 老花眼是由于透镜顺应性降低。 结果 这些研究的结果将进行定量比较， 一项关于人类调节和老花眼的同等研究， 目前正在PI的实验室进行。 人类和恒河猴 猴子在遗传学上是紧密相连的，它们的视觉 系统在两个方面表现出很强的定性相似性 近视眼的发病机制和发展， 在许多方面数量上不同。 拟定的研究将 允许表征以下因素之间的共同点： 这两个物种，并提供了对具体作用的深入了解 非共享质量（例如， 不连续性）在图像形成和聚焦过程中。

The mechanism by which accommodation occurs in the human eye is currently a matter of controversy, attributed variously to the action of the ciliary muscle through the zonular apparatus, the hydraulic action of the vitreous on tba anterior segment, or some combination thereof. Resolving this controversy is a matter of importance, since the age-dependent loss of accommodative amplitude - presbyopia - can only be understood, and perhaps arrested, through an understanding of the aging of the accommodative mechanism. The long-term goal of this research, then, is to characterize the aging of the acccmmodative process in the human eye. This grant proposal is specifically concerned with accommodation and the development of presbyopia in the rhesus eye. Adult rhesus accommodation and accomodative loss will be modelled analytically, with the forces needed to act on the lens determined from a description of lens deformation during a small accomodation; changes in the magnitude and/or pattern of forces with age will help to define those factors whose aging contributes to accommodative loss. A second type of modelling approach - finite element analysis - will also be employed to expand the scope of the study without the necessity of developing an even more complex analytical formulation. Computer-based ray-tracing studies will be used to characterize image formation in the adult eye, and will be compared to humans. Characterization of the complex elastic properties of the rhesus monkey lens using dynamic shape analogy modelling of its behavior in a harmonic oscillator will also be performed, providing not only the necessary elastic constants for the accommodation models, but also testing directly the hypothesis that presbyopia is due to decreased lens compliance. The results of these studies will be quantitatively compared to the results of an equivalent study on human accommodation and presbyopia, currently underway in the PI's laboratory. The human and rhesus monkey are closely linked phylogenetically, and their visual systems exhibit strong qualitative similarities in both accommodative mechanism and the development of prestyopia, while differing quantitatively in many respects. The proposed study will allow the characterization of factors shared in common between these two species, and provide an insight into the specific role of non-shared qualities (e.g. the number of the zones of discontinuity) in image formation and the focussing process.