Image of the retina of a healthy subject acquired using adaptive optics scanning laser ophthalmoscope imaging (AO-SLO) showing both cone and rod photoreceptors. The image on the left is taken around 6.5° measured down from the fovea (A). Image (B) shows a zoomed-in section of image (A); cones are marked in green and rods in red. Adapted from the article of Merino et al [16].