Pupil motion analysis and tracking in ophthalmic systems equipped with wavefront sensing technology

Our eyes are constantly in motion, even during "steady" fixation. In ophthalmic systems equipped with wavefront technology, both eye and head motion potentially degrade its performance and/or increase the cost and complexity, as they induce a movement of the entrance optical pupil of the system. Here, we characterize the pupil motion in an aberrometry setting, using a custom, high-speed pupil tracker (478 Hz), and draw conclusions on design considerations of future ophthalmic systems. We also demonstrate the feasibility of tracking such motion directly with a custom-built Hartmann-Shack sensor (236 Hz) using a method that offers certain benefits over previously suggested approaches, thereby paving the way to an efficient and cost-effective approach.