A demo of a human eye I made in Blender for a character in my WIP submission for the Weekly CG Challenge #129. Featuring customisable eye colours and shape-keys for dilation.
Rendered in Cycles using the Principled BSDF shader, which worked really well for this purpose. Having an integrated clearcoat layer meant I could apply a bump map to the veins underneath the surface of the eye to get the realistic look of detail under the thin surface of the eye, plus a small touch of subsurface scattering through the eye.
Thanks to César Salcedo for providing the textures, it made it very simple to get straight into shader work and lighting work.