Why is my material index not working on the other eye? I have a robot with a monocle on one eye, and now I want to give his eyes a glare effect. So what I did is, I gave the emission material that is assigned to the eyes a pass index of 1. But after the render the eye behind the monocle wasn't detected. And the glare effect only worked on the open eye.

What would be the best way to add glare to the eyes in this situation?
My best thought is make sure you have the blue part of the eye as a separate material index. Then use that as a factor for black and the original image. This will separate the eyes from the mesh.

Afterwards, you can use a glare node on the eyes. If you where to following this work flow make sure the threshold low.