Multispectral Near-infrared Imaging Technologies for Nonmydriatic Fundus Camera

A strong flash of light is required to obtain a clear ocular fundus image by conventional fundus camera. Patients undergo a dazzling experience, and the pupils of their eyes constrict, making it difficult to obtain continuous images or videos without a mydriatic agent. To avoid a lack of comfort experienced by the patient, we have developed a fundus camera that can be used to acquire colorized images from the combination of multispectral near-infrared (NIR) images. In this study, the optical system of a fundus camera, an on-chip NIR bandpass filter design, a fabrication process for a low-cost and compact multispectral NIR camera, and a prototype of a selfie fundus camera are discussed. We also describe a tracking technology of fixational eye movements and denoising by averaging the stabilized images.