Figure 1.

Left: 20 AO image frames, each measuring 4° × 4°, are acquired at the coordinates marked by the black dots, to cover the area of retina shown in red. Areas of overlap between AO frames are depicted by the darker shades of red. The 12 loci studied here are shown by the blue boxes. Center: For analysis of single AO frames, the internal target in the AO device is set at each of the 12 coordinates of interest, and the sampling windows are extracted from the center of each AO frame. Right: In the ideal situation, the position of a gaze-directed single AO frame exactly matches its retinal location relative to the anatomical fovea (top). It is possible that the positon of the preferred retinal locus (blue dot) does not match the position of the anatomical fovea (yellow dot), so that the actual position of the single AO frame is translated relative to the intended coordinates being studied.