Patent ID: 7815310

Claim:
An apparatus comprising: an internal fixation/visual acuity projector module configured to project a selected pattern display; a beam directing element configured to direct a portion of the selected pattern display towards a patient's eye; a sub-wavefront focusing lens configured to focus a returned sub-wavefront to an image spot on a focal plane, with the returned sub-wavefront being a portion of a wavefront returned from the patient's eye, where the wavefront is generated by a light source with the light source being separate from the internal fixation/visual acuity projector module; a sequential wavefront scanning device configured to sequentially shift the returned wavefront by a first displacement in a first dimension and a second displacement in a second dimension so that different portions of the wavefront are sequentially projected onto the sub-wavefront focusing lens; a variable aperture configured to control the size of the sub-wavefront to be focused by the sub-wavefront focusing lens; a position sensing device, located substantially at the focal plane of the sub-wavefront focusing lens, configured to indicate the two-dimensional displacement from a reference point of the image spot on the focal plane; and a controller, coupled to the variable aperture, scanning device, and internal fixation/visual acuity projector module, configured to coordinate the operation of the variable aperture, the scanning device and the internal fixation/visual acuity projector module.