The iris object contains a shape key for this, it is called " Pupil contract"
Of course, this is a full and updated version.
Yes, in the new version 1.2 reptilians and cats iris have been included
The generator will work on any PC that supports Blender, but an i5 processor or higher is recommended. It would also be positive to have a decent graphics card.
The textures will be generated automatically only by pressing the F12 key in the scene: Visualization fast (only emission). No more action is required. The file will be saved by default in the "C: \ Eye generator" directory.