Research On Vision Correction Of Individual Human Eyes Based On Eye Model

This research concentrates on the study of setting up individuated human eye model and its correction with wave-front technology. The main contents as followed: First of all, the physiological configurations of human eyes, the basic concepts of eye aberrations and its mathematical expression, the measurement of eye aberrations, the theory of Hartmann-Shack wave-front sensor and the developments of eye model are introduced briefly. Then setting up the individuated human eye model with the Zemax optical design software based on the data from corneal topography, eye's axial lengths and wave-front aberrations. Finally, design frame glasses and contact lenses which can correct the wave-front aberrations of the eye model and analysis their position tolerances of rotation and in-plane rotation.Measure the corneal topographies of both anterior surface and posterior surface of the cornea, by the Orbscan-II corneal topography measurement machine to construct the individuated cornea in Zemax software; measure the eye's axial lengths by the BMF-200 eye A/B type ultrasonic thickness measurement machine to calculate the thickness of cornea, the length between posterior surface of cornea and anterior surface of lens, the thickness of lens and the length between lens and retina; measure the wave-front aberrations by the Hartmann-Shack wave-front sensor and make use of the optimization function in Zemax software to get the individuated human eye on the basement of Gullstrand-Le Grand eye model. Choose the operand Zern, set target is zero and the variables are radius and non-spherical surface parameters.Design the individual frame glasses to correct the wave-front aberration. The material is colophony, and the surface type is non-spherical. We choose the Zernike coefficients as operand, the target is zero, and the variables are the radius and the non-spherical parameters. We find that the frame glasses can correct the aberrations greatly by analysis the wave-front aberrations before and after corrections. Considering the lightly offset when using the frame glasses, we study aberrations for different offsets and find that our frame glasses can correct all aberrations under 0.2R(R is the radius of pupil) offset, while can't correct some high order aberrations at 0.25R. This means 0.2R is the tolerance for high order aberrations of the design frame glasses. When the offset get 0.3R, partly of the low order aberration can't be corrected either, means 0.25R is the tolerance for low order aberrations.Design the individual contact lenses to correct the wave-front aberration. The material is PMMA, and the surface type is non-spherical. We choose the Zernike coefficients as operand, the target is zero, and the variables are the radius and the non-spherical parameters. We find that the contact lenses can correct the aberrations greatly by analysis the wave-front aberrations before and after corrections, and get a better effect than the frame galsses. Considering the contact lenses will move and rotate with eyeball,we study aberrations at different offsets and angles. The tolerance for high order aberrations of in-plane rotation is 0.05R, while for low is 0.075R; the tolerance for high order aberrations of rotation is 2°, while low has no affect under 5°rotation.