Sampling geometries for ocular aberrometry: A model for evaluation of performance.

The purpose of this work is to outline a simple model to assess the relative merits of different sampling grids for ocular aberrometry and illustrate it with an example. While in traditional Hartmann-Shack setups the sampling grid geometries have been somewhat restricted by the geometries of the available microlens arrays, other techniques such as laser ray tracing or spatially resolved refractometry allow for a greater freedom of choice. For all available setups, including HS, it is worth studying which of these choices perform better in terms of accuracy (closeness of the obtained results to the actual ones) and precision (uncertainty of the obtained results). Whilst the mathematical model presented in this paper is quite general and it can be applied to optimise existing or new aberrometers, the numerical results presented in the example are only valid for the particular aberration sample used and centroiding algorithms studied, and should not be generalised outside of these boundaries.