Guppy
Use "Toggle Subdivision Surface" button on left toolbar. This model actual has multiple layered eyes and internal organs, as the real life fish is semi-transparent and so internal organs are somewhat visible.
I can provide files if you want to see internal modeling.
Also, due to limitations of the web viewer, you can see through one of the eyes and get a rough idea. Turn on "Double Sided Shading" to get rid of this rendering error.