how to make 2d pupil on 3d eyeball for rigs?

I know, But please there got another way to make it easier. I need to rig the 2d pupil to track to follow it. and please show demonstrate pictures or upload blends file.

see this picture below as an example: Her 2d eye moves around the 3d head.

enter image description here

Welcome :tada:

this may be not the best introduction to a community… you are asking a question… but know it already ? But then you don’t talk about your way but ask about a better way ?? How should we know :question: And your image description is telling us what ???
If you tell what you have found in the net or here on BA then there would be a much greater chance to get an answer or a better starting point for a disccussion… I remember myself some similar questions/discussions here on BA.
(…you know there is a search button on the top right ? … the magnifier icon… :mag: )

So if you can elaborate this a bit more i’m sure there is anyone eager to help.