The Study And Design Of Natural Refractor’s Optical System

The optical system directly effects natural refractor’s performance and the result of measurement, as the core system. Based on the research of various kinds of refractor’s optical systems’characteristic, an open-window type optical path is proposed to limit eye’s self-adjusting, taking the place of fog system.Based on the designed open-windows type optical structure, researched the optical imaging characteristics through theoretical analysis and experiment, a new method of optometry by measuring the ring thick of the reflection image, rings thick method for short, is proposed. At the same time, a focusing optical path is designed for the rings thick method.By studying on the optical imaging characteristics of the focusing optical system in refractors, firstly a relationship between the movement of the focusing component and diopter is built, and the initial structural parameters of system are designed. Then, the focusing optical system is modeled by using zemax software. At the same time,-20D,-15D,-10D,-5D, OD,5D,10D,15D,20D, these nine eye models and the open-window optical path model are built with zemax too.By the modeling and optimize function of zemax, the designed parameters of optical system are decided. Use the optical system to simulation optometry on the nine eye models, and the relative error is under6%. At last, the nine simulation eyes are measured with building a corresponding testing platform, and the relative error is under7%. The test result shows that it is reliable to use the designed optical system of natural refrectometer to optometry.