Design of an Optical System for Nonmydriatic Stereoscopic Imaging Fundus Camera

摘要

This study aimed to propose the design of a new stereo imaging optical structure for the fundus camera. An optical system for the nonmydriatic stereoscopic imaging fundus camera with a field of view of 30 degrees was designed to address the problem of capturing only one retinal image by the existing fundus camera. The new system could realize multiangle synchronous capturing of retinal images, making it possible to reconstruct a 3D fundus based on stereo vision. It comprised an illumination system and an imaging system. In the illumination system, the central ghost produced by the ophthalmic lens was eliminated by setting black spot plates, and an annular aperture was added to prevent the generation of stray light. In the imaging system, a new fundus imaging structure was designed based on the principle of Greenough stereomicroscope imaging. The result showed that the resolution was more than 110 Ip/mm, the value of the field curve was less than 18 mu m, the distortion value was -2.2%, and the chromatic aberration of all field of view was within the Airy disk. It came to a conclusion that the imaging system had strong focusing abilities, and adapted to different eyes from -10D to +5D (1D = 1 /m).