Figure 8:

In the AOSLO, the stimulus is printed directly onto the retina by modulating the scanning laser, line-by-line, as it scans a raster pattern on the retina. The upper cartoon shows a situation where the scanning beam is been modulated to project a letter ‘E’ on the retina. Lower left: The image that the subject sees. Lower right: An actual single frame image from a video showing what the operator sees. The modulated letter is directly encoded onto the retinal image, in this case showing the mosaic of cones. In this way, the operator can ensure that the stimulus is focused accurately on the cones and can also determine exactly which cones have interacted with the stimulus during its presentation.