Talk:Eyeball
Iris Material
It would seem that in the OB engine, the iris material is in fact a property of eyeball material. Here's the contents of the VMT file "eyeball_r.vmt"
"eyes" { "$basetexture" "models/Humans/Female/eyeball_r" "$iris" "models/Humans/Female/pupil_r" "$halflambert" 1 }