Eyes are rendering with no color.

Here I have a MakeHuman model I have been working on with the goal of photorealism:

Notice that the eyes reflect a white plane. That is just my light emitter.

The problem is that my eyes do not render properly. I have employed diffuse, transparent, glass and glossy BSDFs to make the eye shiny and reflective. However, the sclera (white part of the eye) are gray. Nothing I do seems to be able to light them up.

I disabled glass and glossy to solve the problem, but the scleras were still gray. I disabled transparency and the eyes turned black.

How can I fix this color issue while maintaining the glossy nature of the eyeball?

My eyeball lighting setup:

The eyeball texture:

Your node setup is a bit odd:

Using constant mixing factors in Mix shaders is hardly ever a good idea: The Mix shader is much more powerful when driven by other nodes.

Why mix Glass and Glossy shaders? Glass already has an inbuilt glossy component.

Why connect the texture’s Alpha to the Color input of glass and glossy shaders?! Alpha is a value between 0 and 1 - what color is supposed to come out of that other than some shade of grey? Take the color coding of the outputs and inputs as a hint: You’re connecting a grey output to a yellow input…

The MakeHuman Eyes use the texture’s alpha to isolate the cornea from the rest of the eye, so the image’s alpha could be used to drive a mix between glass and diffuse:

The Light Path node prevents the glassy parts from casting shadows, which should keep the color parts brighter.

The problem is solved.

This is what I got: