Real Time Pupil Size Monitoring As a Screening Method for Diabetic Retinopathy

This paper reports an accurate pupil size monitoring and analyzing system designed for a new method for screening diabetic retinopathy. The system monitors the pupil size change under stimulation of circular or annular objects of different sizes and brightness produced on a LCD screen facing the subject. Pupil response is captured by digital cameras and the eye images acquired are processed in real time. A novel algorithm is designed to calculate the pupil size to provide data input for the screening procedure of diabetic retinopathy. To distinguish real pupil size changes from artifacts like blinking, eyelid drop or reflections, we use several image processing techniques to estimate the pupil size when the pupil shape is partially occluded.