A 9.3× continuous zoom optical system with fixed finite conjugate distance was designed for E-vision aid device.By using optical design software,the configuration of the optical system and the evaluation of the optical performance including modulation transfer function,spot diagram and diffuse spot in diameter were investigated.The stability of the system performance was forecasted by using the tolerance sensitivity analysis and Monte Carlo method.This mechanically compensated zoom lens combines four group components including a fixed front element,moving variator,compensator,and a fixed rear element with a total of 11 pieces of lens.The optical system which has a tube length of 76 mm and a front intercept distance of 262 mm can realize continuous zoom from 8.8- 52 mm without any image vignetting or obvious fluctuation in image quality.