Objects behind glass shader appear black Why is this Iris not showing? It worked previously, before I started working on the fur and particle system today and other parts of the model (a monkey model) and at the end I realised that the Iris disappeared. I haven't touched the eyeball, but now the iris doesn't show. I suspect that it has to do with the UVs, but everything is in place, I didn't tweak anything, it should work. I'm attaching a stripped down .blend (only the eyeball) and a screenshot. Can someone have a look into the file, and try to make the iris show?

I should also note, that when I open the previous file, it shows. But when I append that eyeball to the new file, it doesn't show.
You are using a glass shader for the cornea. 
Unfortunately that shader does not behave as expected when it comes to letting light through it...

You need to add some transparency to it in a node setup like this:



For a more detailed explanation read: How to illuminate the darkness inside glass objects in Cycles?