Figure 9B. Pigments in oil droplets. Oil droplets such as these from the retina of a Red-eared Slider (Pseudemys scripta elegans), frequently contain pigments so that light at particular wavelengths is strongly attenuated. In this case there are five types of oil droplet, four of which are easily discriminated visually (the "clear" droplets actually form two different spectral classes). The retina is whole-mounted here, and the light used to generate the image passed through the photoreceptors in the normal direction. Figure from Ahnelt et al. (2000). See Figure 9A, Figure 9C.