A non-mydriatic fundus camera designed with two-channel illumination

With the improvement of people's health awareness, portable fundus cameras for health monitoring are popular. In order to solve the problem of non-mydriasis in fundus cameras based on new smart phones, we propose a dual channel lighting non-mydriasis method. The system focus with 680nm light, and captures color images with white light flash. In this study, a group of orthogonal polarizers were used to eliminate the stray light caused by the front eyepiece, and a circular light source was used to suppress corneal reflection. The system performs well with a field of view of 45° and a pupil diameter of 3mm, when refractive error ranges from -10D to +10D. The imaging quality of the system is good in 480- 700nm band. This study provides a reliable scheme for telemedicine of senile ophthalmic diseases.