Textures & Shaders
For the render I've used Mental ray in 3dsmax. The reason for this is because I like to use the Fast skin shader, as it's a good shader and with it, I have a lot of control over maps.
For the final shader, I've painted these maps.
Here are the parameters that I used on the shader.
But the values can be different for others models, because they use the scale of the object, so you have to make some render tests to get a better result. one tip is try some values on the scale factor parameter.
The shader for eye is very simple, just a phong shader with a high value of specular, the secret here is the way that it was modeled, two separated meshes, one for iris and the other the cornea. I've used two different materials, for the cornea I've used a raytrace material with a fallof on refraction parameter and a high value of specular too.
With this and some tricks on reflection, I get this result.