设计了一款便携式39°视场免散瞳眼底相机光学系统, 可以对-10~+15m-1屈光度变化范围内的人眼视网膜清晰成像。采用环形光源照明, 使眼底视网膜照明均匀度达到95%, 也很好地消除了角膜反射。加入的信标系统使得便携式眼底相机光学系统在拍摄时有助于保持人眼与成像系统的同轴度, 进一步提高拍摄视网膜图像的清晰度。通过对成像系统的优化设计及仿真分析, 得到均方根直径小于6.4μm、场曲小于60μm、像散小于50μm、畸变小于3.6%, 在67lp/mm处各视场传递函数值大于0.5和成像系统加工良率高的眼底相机光学系统方案。方案可以应用于眼科检查, 改善全国偏远地区眼科医疗器械缺少的情况。

A portable and mydriasis_free fundus optical system with 39° field of view (FOV) is designed. Legible retina images of eyes in which vergence ranges from -10~+15m-1 can be received by this system. An annular light source is adopted to effectively eliminate the stray light reflected by cornea and the retinal illumination uniformity can be up to 95%. The retinal image quality can be improved by the beacon system, which contributes to maintain the coaxiality of the human eye with the imaging system while the fundus optical system is working. Through optimization design and simulation analysis of the imaging system, a fundus optcial system with great fabrication feasibility is designed. Results show that the modulation transfer function (MTF) values of all fields are higher than 0.5 at 67lp/mm with root-mean-square (RMS) less than 6.4μm, the field curve is less than 60μm, the astigmatism is less than 50μm and the distortion is less than 3.6%. The program can be applied to improve the lack of ophthalmic medical devices in remote areas of the country.