| A parametric 3D geometry model of human crystalline lens is established, and an interactive and a realistic 3D lens display system using VC++ and OpenGL is developed in this paper. Firstly, a standard lens model is constructed based on the published experimental data of the lens profile. Then, the lens shape can be adjusted to satisfy certain restricting conditions and geometry topology relation by inputting clinical characteristic parameters such as lens diameter, lens thickness, lens nucleus diameter, lens nucleus thickness and nucleus equatorial offset. Thus, the presented model can be used to characterize various lenses of the different people. To make the model more realistic and to show the lens cortex as well as the nucleus, special effects such as lighting, transparence and blending are applied on the model using the popular graphic interface OpenGL, furthermore, rotate and zoom functions were introduced to the model lens so that the user can view the lens from the any angle and any distance. After finished the above geometry modeling, we explore preparatory physical model. It includes two parts, the first is lens optical power computation and the other is 2 dimensional lens accommodation simulations. To conclusion, the parametric modeling method proposed in this paper realized the three dimension visualization of lens of the China virtual eye;It provides an available basis for the further studies on lens accommodation and surgical simulation research.Followings are innovations of this thesis:1. Established a parametric 3D geometry model of human crystalline lens. It can be used to characterize various lenses of the different people.2. Implemented the model reconstruction from partial to integer. According to the partial lens image collected by Slit Lamp, using curve fitting, to create the whole lens contour and construct 3 dimension model.3. Developed a user-drive lens 3-D visualization system, and the preparatory physical model is established. |
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