Comparative Results from Shack-Hartmann and Distorted Grating Wavefront Sensors in Ophthalmic Applications

The aim of this work was to determine the relative performance of a Shack-Hartmann (SH) wavefront sensor and a distorted grating wavefront curvature sensor (DGWFS) when used to measure the aberrations in the human eye. Previous work carried out by Kestrel and others suggests that the DGWFS is able to successfully reconstruct wavefronts in severely scintillated conditions in which SH sensors typically fail to give a good reconstruction. The poor performance of conventional SH sensors in scintillated conditions prevents their use in ophthalmic aberrometers with human subjects who have medical conditions such as cataracts. This limitation substantially restricts the percentage of the population that can take advantage of emerging technology enabled by having accurate aberration data for the anterior segment. The SH sensor utilized has a novel dithered reference source which mitigates scintillation problems. However, the DGWFS potentially offers a simpler, lower cost and more robust solution.