Opthalmic instrument having wavefront sensor with multiple imaging devices that simultaneously capture multiple images of an array of spots produced by a lenslet array

An improved ophthalmic instrument including a wavefront sensor that estimates aberrations in reflections of the light formed as a spot image on the retina of the human eye. The wavefront sensor includes a beam splitter operably disposed between a lenslet array and multiple imaging devices. The lenslet array forms a first array of spots, and the multiple imaging devices capture multiple images of the first array of spots for use in estimating the aberrations of the eye in a manner that minimizes the adverse effects of eye movement on the accuracy of such estimates. The beam splitter preferably comprises a prismatic beam splitter that splits light incident thereto into multiple arms. The multiple image devices may capture at least a first image of the first array of spots at best focus and a second image of the first array of spots near best focus for use in dynamically identifying sub-arrays (pixel areas) of the Hartmann spot imaging device (e.g., the imaging device that will be used for the determination of Hartmann spot positions) that avoid dot crossover for a particular wavefront measurement. An additional imaging device may be operably coupled to the beam splitter to capture at least one image of the pupil image plane of the lenslet array for use in identifying fiducial points therein (or for automatically identifying lenslet centers therein), thereby minimizing the adverse effects of eye movement on the accuracy of such measurements.