An accommodating opto-mechanical model of the aging human eye

The objective of this paper is to create a new accommodating opto-mechanical model of the aging human eye for basic optical and mechanical simulations. This model can be used for the evaluation and simulation of laser treatments of presbyopia or other diseases of the human eye. The presented eye model contains a lens, structured by cortex and nucleus, which is mechanically simulated by a finite element model (FEM) with the program ANSYS. The model is orientated on physiologically measured values describing the dependences of geometrical lens parameters on age and accommodation. The results of this mechanical simulation are used as input for a complete optical eye model, implemented in the software ZEMAX. The optical performance of the model corresponds with clinical data. The resulting joined opto-mechanical model describes the accommodation of the aging eye. Established optical eye models like those of Koretz et al., Dubbelman et al. and Norrby are used as reference to show the level of correspondence between them and the eye model presented here. Due to a different approach, the presented model makes it possible to explain the changes in the geometric optical parameters during accommodation; for this purpose it uses the changes caused by the stiffness and the effecting forces in the mechanical lens model. The model is suitable for different optical simulations especially for theoretical investigations to develop treatment methods of presbyopia. The state of presbyopia is controlled by the stiffness choice in the mechanical lens model.