Ophthalmic wavefront measurements using a versatile pyramid sensor

We describe the operation of a pyramid wavefront sensor used to measure and correct aberrations of the human eye. The system is designed for maximum speed when running in closed loop but can also provide calibrated open-loop measurements of aberrations with a range of sampling options. A detailed characterization of the system was performed to ensure measurement accuracy. Ocular aberrations after correction had root-mean-square errors consistently less than 0.1 μm over a 6 mm pupil for all subjects tested. The system frame rate is 83 Hz in both open- and closed-loop modes.